Labour's leader in Scotland Jim Murphy would lose his East Renfrewshire seat to the SNP if today's polls were reflected on election day. However, the SNP's Kirsten Oswald leads Murphy by only three points - down from a nine-point lead in the previous poll.
The survey suggests increasing numbers of Scottish Tories are willing to lend their vote to Murphy to keep the SNP out.
There was bad news for the Tories' only seat north of the border, with the SNP 11 points ahead of Conservative candidate David Mundell on 39 per cent.
Down south, there were varying results from the Tory-Labour marginals.
In the battleground of Croydon Central, the Conservatives have reversed a four-point Labour lead to a four-point Tory lead. This result would see Gavin Barwell re-elected in a key London constituency.
Labour have increased their lead in Norwich North to two points. The seat is number 52 on Labour's target list and is being defended by the youngest Tory MP of the last parliament, Chloe Smith.
The Tories will be pleased that they have leads in Battersea, Pudsey and Stourbridge. Pudsey is an important bellwether seat.
Voting intention in my final round of marginals polling. With a week still to go, they’re snapshots not predictions: pic.twitter.com/vrMFNGoA56— Lord Ashcroft (@LordAshcroft) May 1, 2015
Labour could win Stewart Jackson's seat of Peterborough on today's numbers with a two-point lead at 34 per cent. Tory minister Esther McVey has cut Labour's lead in her Wirral West patch from five to three from last month.
In Nick Clegg's seat of Sheffield Hallam, the Lib Dem leader improved his chances of re-taking the seat. Clegg is on 36 per cent, just one point behind his Labour challenger Oliver Coppard. In March, Labour had a two-point lead.
In total, Ashcroft has conducted a quarter of a million interviews over a year and a half. The Tory peer's polls have become crucially important to the political parties and are a must cover event for political hacks.
Ashcroft says on his website that his interest in polling began in the run-up to the 2005 General Election when he conducted research into why the Tory party was failing to recover after their hammering in 1997.
He was asked to become deputy chairman of the Conservative Party by David Cameron and offered the party analysis of public opinion.
He continued to provide polling on a constituency and national level open to the public after leaving his role as deputy chairman of the Tory party.