One thing’s for sure in the up-coming Oldham West & Royton by-election: neither Labour nor Ukip are taking electoral victory for granted in what is going to be a bitterly fought contest.
In leader Jeremy Corbyn’s first electoral challenge since taking the reins of the Labour party, his party won’t take any chances: it’s up against a party that has either won or come in second place in the last seven by-elections in England.
To look at how Thursday's by-election is likely to play out, we've analysed the by-elections that took place over the course of the last Parliament.
Ukip’s candidate, John Bickley, is not inexperienced: he has come in second place to Labour in two by-elections in the last two years, most recently losing by just 617 votes to Labour’s Liz McInnes in Heywood and Middleton – a constituency not far from Oldham West & Royton.
Result: Mark Reckless, Ukip (42.1 per cent); Kelly Tolhurst, Conservative (34.8 per cent); Naushabah Khan, Labour (16.8 per cent); Clive Gregory, Green (4.2 per cent)
Ukip was looking for its second Westminster MP in a by-election that came just a month after Douglas Carswell had won Clacton-on-Sea’s vote.
Triggered by Mark Reckless’ defection to Ukip, he retained the seat.
On the same day, Labour’s Emily Thornberry tweeted a picture of a house with a white van parked outside, leading to her eventual resignation from the shadow cabinet.
Result: Liz McInnes, Labour (40.9 per cent); John Bickley, Ukip (38.7 per cent); Iain Gartside, Conservative (12.3 per cent); Anthony Smith, Liberal Democrat (5.1 per cent)
Ukip’s strategy had been to aim for Tory seats in the South and Labour seats in the North, and with this 2014 target seat, Farage’s party came within a whisker of Labour.
The Ukip candidate was John Bickley – the man who will be competing in Oldham West & Royton’s by-election.
He lost the seat by just 617 votes, hot on the heels of Labour’s Liz McInnes, who replaced the late Jim Dobbin, the son of a coal miner who died during a European trip after drinking Polish vodka.
Result: Douglas Carswell, Ukip (59.7 per cent); Giles Watling, Conservative (24.6 per cent); Tim Young, Labour (11.2 per cent); Chris Southall, Green (1.9 per cent)
Douglas Carswell walked away from the Conservatives to join the People’s Army in August 2015, triggering a by-election in order to win the support of the people of Clacton.
He said at the time that he was frustrated with the Conservative party as they were not “serious about the change we need” and has since said he would never join the Conservatives again.
Carswell won, becoming Ukip’s first Westminster MP, overcoming Giles Watling of the Conservative party.
Result: Robert Jenrick, Conservative (45 per cent); Roger Helmer, Ukip (25.9 per cent); Michael Payne, Labour (17.7 per cent); Paul Baggaley, Independent (4.9 per cent)
Conservative Robert Jenrick saw off Ukip’s Roger Helmer – a former Tory MP – with the Liberal Democrats relegated to sixth place.
While the Conservatives won the seat, Ukip more than halved the party’s 16,000 majority it had gained at the 2010 General Election and increased its vote share by 22.1 per cent. Yet, while this was the first electoral test since the European Elections, which Ukip won, Farage’s party did scare more than a few Tories.
Result: Mike Kane, Labour (55.3 per cent); John Bickley, Ukip (18 per cent); Rev. Daniel Critchlow, Conservative (14.5 per cent); Mary di Mauro, Liberal Democrat (4.9 per cent)
Another second place for Ukip, overpowered by a Labour victory , but on a vastly reduced turnout: turnout was just 59 per cent of what it was at the 2010 General Election.
And there’s that man again, John Bickley, in second place, for Ukip. But Bickley did increase the party’s vote share by 14.5 per cent.
Meanwhile, the Liberal Democrats couldn’t even garner enough support to get their deposit back.
Result: Emma Lewell-Buck, Labour (50.4 per cent); Richard Elvin, Ukip (24.2 per cent); Karen Allen, Conservative (11.5 per cent); Ahmed Khan, Independent (5.4 per cent)
Another North East win for Labour, with Emma Lewell-Buck overwhelming Ukip’s Richard Elvin to retain the seat Labour has held since 1935.
The election coincided with local elections across England, during which Ukip made huge gains, with 24 per cent of the total vote. It also increased its share of seats in county council elections on the same day.
The by-election was triggered by the departure of former shadow foreign secretary David Miliband, who had held the seat until 2001.
Result: Francie Molloy, Sinn Féin (46.9 per cent); Nigel Lutton, Independent (34.4 per cent); Patsy McGlone, SDLP (17.4 per cent); Eric Bullick, Alliance (1.3 per cent)
Sinn Fein held the seat of Mid Ulster, which was left vacant for a year when Martin McGuinness stepped down as an MP at the end of 2012.
Francie Molloy won the seat but witnessed the party’s majority fall by over 10,000 votes from the 2010 General Election victory.
Sinn Fein have a policy of abstentionism from Westminster, with its MPs choosing not to sit in the House of Commons but lobbying the government on behalf of their constituents.
Result: Mike Thornton, Liberal Democrat (32.1 per cent); Diane James, Ukip (27.8 per cent); Maria Hutchings, Conservative (25.4 per cent); John O’Farrell, Labour (9.8 per cent)
In admitting he had perverted the course of justice over driving licence points, Liberal Democrat Chris Huhne had little choice but to stand down and trigger a by-election.
They held the seat - not that it did them much good in the ensuing General Election, where they lost the seat to the Conservatives.
In this by-election, the Lib Dems’ share of the vote fell more than 14 per cent since the 2010 General Election.
Result: Steve Reed, Labour (64.7 per cent); Andrew Stranack, Conservative (16.8 per cent); Winston McKenzie, Ukip (5.7 per cent); Marisha Ray, Liberal Democrat (3.5 per cent) Labour managed to hold on to Croydon North in a by-election caused by the death of Malcolm Wickes.
Steve Reed won on an incredibly reduced turnout – some 27,114 fewer votes were cast for Reed than when Wickes took the seat in 2010.
The Conservatives managed to secure second place – though only with 4,137 votes to Reed’s 15,898.
Result: Andy McDonald, Labour (60.5 per cent); Richard Elvin, Ukip (11.8 per cent); George Selmer, Liberal Democrat (9.9 per cent); Ben Houchen, Conservative (6.3 per cent)
Middlesbrough returned a Labour MP after the death of Sir Stuart Bell triggered a by-election.
Meanwhile, Ukip clinched another second place. Candidate Richard Elvin said: "There can be no doubt that Ukip is on the up. Ukip is now the only political party which we can truly say can take the fight to Labour in the North East."
Result: Sarah Champion, Labour (46.5 per cent); Jane Collins, Ukip (21.7 per cent); Marlene Guest, BNP (8.4 per cent); Yvonne Ridley, Respect (8.3 per cent)
Prompted by the resignation of Denis MacShane, who submitted 19 false invoices “plainly intended to deceive” to the parliamentary expenses authority, candidate Sarah Champion took the seat, leaving Ukip’s Jane Collins to eat her dust.
But, as with the vast majority of by-elections, turnout was lower, at 33.8 per cent - down from 59 per cent in the 2010 General Election.
Result: Stephen Doughty, Labour (47.3 per cent); Craig Williams, Conservative (19.9 per cent); Bablin Molik, Liberal Democrat (10.8 per cent); Luke Nicholas, Plaid Cymru (9.5 per cent)
With a turnout of just 25.65 per cent, down more than 60 per cent from the 2010 General Election, Labour managed to hold onto the seat.
Stephen Doughty replaced Alun Michael, who stepped down to stand in the police and crime commissioner elections. He won the seat with 9,193 votes, a majority of 5,334 over the Conservatives.
Labour has held the seat since it was created in 1983, one of the largest seats in terms of number of voters.
Result: Andy Sawford, Labour (48.4 per cent); Christine Emmett, Conservative (26.6 per cent); Margot Parker, Ukip (14.3 per cent); Jill Hope, Liberal Democrat (5.0 per cent)
The seat, formed in 1983, had been held by Labour since 1997, but was taken by Louise Mensch at the 2010 General Election. In 2012 she stepped down - and Labour regained its seat.
Sawford declared voters had delivered a "damning verdict" on Cameron, although he hit back that it was nothing more than a "classic mid-term result".
Result: Lucy Powell, Labour (69.1 per cent); Marc Ramsbottom, Liberal Democrat (9.4 per cent); Matthew Sephton, Conservative (4.5 per cent); Chris Cassidy, Ukip (4.5 per cent)
Manchester Central was taken by Lucy Powell and the Labour party, but on a turnout of just 18.2 per cent of eligible voters, down from 47 per cent in 2010.
In terms of the share of vote lost, it was the Lib Dems’ worst result in a by-election since World War II.
Former Labour incumbent Tony Lloyd resigned the seat to fight and win the position of Police and Crime Commissioner in the Greater Manchester Police area, triggering the by-election.
Result: George Galloway, Respect (55.9 per cent); Imran Hussain, Labour (25 per cent); Jackie Whiteley, Conservative (8.4 per cent); Jeanette Sunderland, Liberal Democrat (4.6 per cent)
The “Bradford Spring” is what George Galloway branded his surprise electoral victory for the Respect party.
Galloway won the by-election by 10,140 votes after having been expelled by Labour in 2003 for comments he made as part of his opposition to the Iraq War, prompting Labour leader Ed Miliband to say the result was “incredibly disappointing”.
The seat, however, was won back by Labour in 2015 by Naseem Shah, with 49.6 per cent of the vote.
Result: Seema Malhotra, Labour (54.4 per cent); Mark Bowen, Conservative (27.7 per cent); Roger Crouch, Liberal Democrat (5.9 per cent); Andrew Charalambous, Ukip (5.5 per cent)
Following the death of Alan Keen, this West London seat was won by Seema Malhotra, garnering 10.8 per cent more of the vote than at the 2010 General Election.
Perhaps most important in a by-election where the top three parties remained in the same order was how all candidates expressed concern over the 28.8 per cent turnout – at the time the lowest turnout for a by-election for 11 years.
Result: Iain McKenzie, Labour (53.8 per cent); Anne McLaughlin, SNP (33 per cent); David Wilson, Conservative (9.9 per cent); Sophie Bridger, Liberal Democrat (2.2 per cent)
Iain McKenzie won the seat with 53.8 per cent of the vote, but the Scottish National Party increased its vote share by 15.5 per cent.
The margin was unexpectedly convincing after a particularly strong campaign by the SNP, while the Liberal Democrats garnered just 2.2 per cent of the vote, down almost 10 per cent from 2010.
But in 2015 the SNP displaced Iain McKenzie with a 55.1 per cent share of vote.
Result: Paul Maskey, Sinn Féin (70.6 per cent); Alex Attwood, SDLP (13.5 per cent); Gerry Carroll; People Before Profit (7.6 per cent); Brian Kingston, DUP (6.1 per cent)
After Sinn Fein president Gerry Adams stepped down to join the Republic of Ireland’s Parliament, a by-election was triggered that resulted in his party retaining the seat under Paul Maskey.
Turnout fell to 37.53 per cent, one of the lowest for Northern Ireland.
Result: Jon Ashworth, Labour (57.8 per cent); Zuffar Haq, Liberal Democrat (22.5 per cent); Jane Hunt, Conservative (15.1 per cent); Abhijit Pandya, Ukip (2.9 per cent)
Labour MP Sir Peter Soulsby stepped down to fight the city’s mayoral race, leaving room for Jon Ashworth to come in to fill his place.
In 2004 the same constituency had a by-election, where the Liberal Democrats took the seat, which was taken back by Soulsby in 2005, before he increased his majority at the 2010 General Election.
Only five candidates fought the election, with the Lib Dems losing 4.4 per cent of their vote share since the General Election.
Result: Dan Jarvis, Labour (60.8 per cent); Jane Collins, Ukip (12.2 per cent); James Hockney, Conservative (8.3 per cent); Enis Dalton, BNP (6.0 per cent)
Labour MP Eric Illsley stepped down, having claimed over £10,000 for council tax in four years.
Pleading guilty to three charges of false accounting and resigning, he triggered a by-election, before being sent to jail for a year.
The seat has been a Labour stronghold since 1935, and Labour managed to increase their majority in the 2011 by-election with Dan Jarvis garnering 60.8 per cent of the vote.
Result: Debbie Abrahams, Labour (42.1 per cent); Elwyn Watkins, Liberal Democrat (31.9 per cent); Kashif Ali, Conservative (12.8 per cent); Paul Nuttall, Ukip (5.8 per cent)
With 2010 General Election winner Phil Woolas having been found guilty by two judges of “knowingly made false statements” about the character of Liberal Democrat Elwyn Watkins, he was banned from holding public office for three years, forcing a by-election in 2011.
But, Labour comfortably won the contest with turnout considerably lower, just 48 per cent of those eligible casting a vote, down from 61 per cent in 2010.
While during the last Parliament seats changed party hands four times in by-elections, demographically, Oldham West & Royton has the makings of a Ukip target seat, and one which Nigel Farage’s party will be keen to win.
Indeed, in two of those four cases the results were Ukip victories, where the same candidates – Douglas Carswell and Mark Reckless – remained as MPs, just for a different party, after they both defected from the Conservatives.
Still, with Ukip coming in second to Labour six times, both parties are set to fight tooth and nail for every vote.