Ukip’s secret weapon: Has Nigel Farage cracked the code to 2015?

A new poll suggests nearly a third of voters would back Ukip if they thought they had a chance of winning. In a political system where credibility is everything, the potential of Nigel Farage's party is truly revolutionary.

Right now, Ukip are showing signs of breaking into a system designed to keep protest parties out of parliament.

The latest national polls put the Kippers in the high teens – today's Opinium/Observer poll puts them on 18% among those likely to vote. In Rochester and Strood, defector Mark Reckless is enjoying a 13-point lead over the Conservatives, according to ComRes research conducted in the four days to October 21st.

This is a seat they shouldn't be winning. A by-election is different from a general election, true, but Mark Reckless' seat wasn't even in a recent list of the top 100 Ukip targets currently held by the Tories. The margin of victory, if reflected by the latest polling, is significant. And it's especially so in the context of a shocking new poll finding out today.

The question was innocent enough. Opinium/Observer poll out today also tested opinion on the statement 'I would vote for Ukip if I thought they could win in the constituency I live in.'

The results were astounding. Forty-nine per cent disagreed outright. Twenty per cent either weren't prepared to indicate either way. And 31% agreed. That's right. Thirty-one per cent. Nearly a third of voters would vote Ukip if they thought the party had a chance.

This matters. It virtually guarantees that Ukip would be forming part of the next government if MPs in the Commons were determined in the same way as those in Holyrood, or Stormont, or in the Welsh Assembly. As things stand it shows that Farage's appeal is not to be underestimated – something activists of all three of the main Westminster parties have displayed a complacent tendency towards doing in this autumn's conference season.

What all this suggests is that there are around 13% of the national electorate who could be persuaded to vote for Ukip. That's double the Liberal Democrats' entire support across the country right now. Many of them will be concentrated in seats where the Conservatives, in particular, are vulnerable.

What Farage must do in the 193 days between now and the general election is win over as many of them as possible. He doesn't need to persuade them that his right-wing, small-minded approach to politics best reflects their views. They already agree with him. The challenge for Farage is demonstrating that their vote will not be wasted in a system where there are 650 separate contests taking place at the same time – and that in the particular contest where they live, Ukip can win.

It all comes down to credibility. And in this fight, let's be clear, the Conservative strategy so far has appeared to be the right one. Defence secretary Michael Fallon was the latest Tory to outline exactly what this is on BBC1's The Andrew Marr Show this morning. People voting Conservative in Rochester and Strood, he argued, "understand Ukip can't deliver with one MP or two MPs. They're not a party that can deliver a government – and they can't above all deliver a referendum."

Nigel Farage with the latest Tory defector, Mark Reckless, who looks on course to win in Rochester and Strood

What Fallon is trying to do is point out, without actually saying it in terms, that the British political system is designed to ensure newcomer parties can't do well. It blocked out the Liberal Democrats for years and now it is doing the same to Ukip. In general elections in the UK overcoming this barrier is incredibly hard. It takes an extraordinary amount of momentum before it's worth even considering the possibility that a breakthrough might be possible. Fallon and the Tories want voters to conclude there is very little chance of Farage achieving it in 2015.

But Ukip have a lot of momentum. And while the Farage bandwagon would not in normal circumstances be rolling powerfully enough to break the system designed to keep them out, in the 2015 contest it might just be able to do so. The deadlock between the two main parties creates a situation where a hung parliament is plausible – and the number of seats a smaller party needs to hold the balance of power is reduced as a result.

This is why the Ukip high command is doing the right thing in aiming high. Senior party figures, the Sunday Times reports today, have decided Ukip will make a serious attempt to win up to 100 seats in 2015. An extra £1.5 million from donor Paul Sykes will fuel their ambitions, which are being quadrupled from their old – already punchy – target of getting 25 MPs.

The potential is there. Research by Dr Robert Ford of the University of Manchester and Dr Matthew Goodwin of the University of Nottingham, the authors of Revolt On The Right, suggests there are 100 seats where Ukip's message would meet with a particularly welcoming audience. They wrote in a blog last month:

"Ukip's ideal seats share key characteristics: they have lots of 'left behind' voters who we also know from our research are the most receptive to Ukip and its policies. These seats also have very low numbers of voters who tend to remain resistant to Ukip, including university graduates, ethnic minorities and people in professional and economically secure occupations. This is a useful first exercise in filtering through all seats to find those where if Ukip stood a candidate and knocked on doors they would probably find lots of receptive voters."

One of the reasons Ford and Goodwin suggest Ukip won't actually win all these seats is that Ukip won't bother fighting all of them. In Louth and Horncastle, for example, the retiring father of the House Sir Peter Tapsell is leaving behind an intimidating majority of over 14,000 – more than enough to outweigh the fact the seat is the fifth most promising in terms of Ukip appeal. But that doesn't mean there aren't winnable seats elsewhere.

By broadening their campaign to cover a larger number of constituencies, Ukip enjoys an exponential increase in its potential voters. It increases credibility nationally as well as locally. It undermines the Tory argument.

And it presents an entirely plausible route for the party to break the system the Conservatives hope will save them.