Wednesday 25 May 2016 5:18 pm

Brexit campaigners need to remember, "its the economy, stupid!"

Less than 30 days to go, and Boris Johnson has been speeding around in a sports car to over engineer a “take back control” metaphor while Nigel has been doing his latest man of the people act outside a pie and mash Café in Essex. Photo opportunities can, of course, make or break any campaign – just asked Ed Miliband. But despite two questionable reports from the treasury and Osborne’s poor track record on deficit reduction, the polls clearly show remain winning the crucial economic argument.

It is not as if leave doesn’t have ammunition to fire. Many City bigwigs, including the CEO of CMC Markets and the co-founder of Marshall Wace, have added their considerable weight behind Brexit. One would think that with this sort of backing, Farage would put down his mug of builder’s tea and go back to his commodities brokerage roots for some snap shots.

Read More: BoE adviser says UK would remain "thoroughly investable" after Brexit

Instead, Farage continues to relentlessly harp on about the need for an “Australian style points base system” for immigration – leading many voters to think he is the only party leader to come up with the concept. But actually, Michael Howard floated the idea way back in 2005. Like his predecessors IDS and Hague, Howard presided over a resounding election defeat based on this message. This should be a lesson to the UKIP leader and the Leave campaign as a whole. While immigration rhetoric drums up a certain amount of support, its “the economy stupid” that will ultimately sway undecided voters.

Immigration and the economy are of course linked around the issue of wage compression. However, the constant scaremongering seems to have drowned out more important factors, such as free trade. With a genuine free trade option outside the EU, the UK would lead the way with zero tariffs on all imports – dramatically reducing import costs. While from an export perspective, the prospect of having a major seat at the table under other trade bodies, such as World Trade Organisation (WTO), could accelerate growth. This is because, like Australia has recently done with the US, we would be free to replicate our own speedy trade agreements with the rest of the world.

Read More: Why Brexit won’t be a disaster (and as former City minister, I should know)

Another fact Leave campaigners are failing to push home is that by removing the shackles of unnecessary red tape, the City can become the long term leader in financial services – above New York and Tokyo. The City could enforce its own sensible regulations with a smarter tax system, without having the draconian EU rules we have seen recently on innovative financial practices such as dark and high speed trading. This is supported by research group Open Europe, who have stated that if Britain adopted the right regulation and pro-enterprise policies, the economy could be more successful outside the EU.

So while it may be too late for the leave campaign to jump off the immigration bandwagon, one can't help think it has missed a trick. Leaving the EU could be vital for long term economic prosperity, it's just a shame we haven't heard why in this campaign to date. Unfortunately for the Leave camp, the failure to articulate this argument leaves them repeating mistakes of other campaigns and ultimately, could cost them on June 23.

City A.M.'s opinion pages are a place for thought-provoking views and debate. These views are not necessarily shared by City A.M.