The European election creeps closer and the smart money has switched from Labour to Ukip topping the poll. A Labour win would be spectacular in its own right as it would probably require a doubling of their 2009 vote share. I confess there was an intake of breath in the ComRes office when our ITV News poll results were in showing an 11-point Ukip lead over Labour. But the naysayers were confounded by a second poll released on the same day showing a nine-point Ukip lead.

The ramifications of a party with no Westminster MPs topping a popular ballot within a year of a General Election puts us into new territory. What everyone, including Ukip themselves, are trying to assess is how that support will translate into an election where voters are being asked to send an MP to Westminster and a Prime Minister into Downing Street.

If 2009 teaches us anything, it shows that European elections give little indication of what might happen a year on. In 2009 Ukip came second with 16.6 per cent of the vote and managed just over 3 per cent in 2010. Much has changed since of course but the lesson is clear – Ukip should not rely on this spike in support. Indeed, a quarter of Ukip European poll supporters say they are ‘unlikely’ to stick with the party through to next year, making them less committed than supporters of either Labour or the Conservatives (only 5 per cent of whom say they are unlikely to vote the same way at the General Election).

This illustrates the mountain Mr Farage and his Party face in the coming year. He is clearly succeeding in harnessing frustration and distrust among the British public: ask pretty much any question of the general public in a poll and Ukip supporters will be more negative than anyone else. But that is not enough, nor is being too narrowly associated with a particular issue. Ukip do well at European elections because people know that is what UKIP is about. At a General Election the question of Britain’s relationship with Europe inevitably is less of an issue, so will Ukip have a broad enough message to appeal beyond their current support?

Of course, Ukip’s European poll-topping is in a low-turnout election. The 38 per cent ComRes recorded for Ukip this week is based on a turnout of 39 per cent. However, Ukip’s share of the vote – and lead – are lower when those who are likely to vote are also taken into consideration as well as just those certain to vote. This could be a problem for Ukip later this month: higher turnout hurts their vote share. So the fact that a quarter of that 38 per cent, on turnout of 39 per cent, are ‘unlikely’ to vote for Ukip next year is potentially a significant problem for them.

Playing to their advantage is that Ukip supporters tend to be old. Old people vote. The Liberal Democrats have historically suffered, notably in 2010, by having young supporters who fail to turn up on Election Day. Building a base of older voters is a sensible (if until now probably unplanned) electoral tactic but for 2015 it would be no surprise to see Ukip with policies designed to appeal to the “grey” vote. With the Conservatives in Westminster voting intention polls losing around 17 per cent of their 2010 vote to Ukip they will be fighting to drag them back aboard the good ship Conservative having enjoyed their Saga holiday on Ukip Island, while Nigel Farage’s team need to produce a brochure strong enough to secure a repeat visit.

What seems to surprise many is that despite a significant amount of mud being thrown at Ukip and Mr Farage, little seems to stick. If anything, it appears to fuel further support. Media stories about Mr Farage’s expenses and eccentric local election candidates came and went with seemingly little electoral damage done: although a third believe Ukip to be a racist party, just as many think they have sensible policies and are more honest than the other parties. Instead of harming Ukip’s fortunes, efforts to smear the Party seem to be proving counter-productive, reinforcing the Party as outside the Establishment and being bullied for it. Cutting Ukip off at the knees requires a cleverer approach than calling them names.

Ukip have a lot of work to do if they want to be fit to fight a General Election, but the balancing act for them is how to get taken seriously as a mainstream political party without being seen as, well, a mainstream political party. Insurgency is always easier, and more fun, than behaving like a party with serious political ambitions. Mr Farage’s decision not to stand in the Newark by-election and therefore eschewing the best chance he has of his Party winning a seat in Westminster will perpetuate the party’s challenger status.

Either way, Ukip are surely doing better than any of even the most optimistic Party members and strategists could have hoped for. So far, this has all just been the preparation, 22 May will be the dress rehearsal, the real thing begins straight after the election as all attention turns to 2015. Keeping hold of their supporters, and broadening their appeal through to a General Election will be their toughest task yet.

Tom Mludzinski is head of political polling at ComRes 

Tags: ComRes, Nigel Farage, Polling, UK politics, UKIP