As I predicted at the start of the campaign, the ‘Poll of Polls’ trend analysis shows how the Conservatives and Labour are starting to pull away from their respective rivals. The Brexit Party’s support is declining relative to the Conservatives, and Liberal Democrat support is declining relative to Labour. We could be heading for another two party contest, much like in 2017, as the two-party system reasserts itself. The big news this week was Nigel Farage’s decision to ‘put country before party’ by standing down in 317 Conservative-held seats. Given that 35 of the 50 smallest Conservative majorities come in Leave areas, this is a significant development. It means that in these seats Conservatives who are fending off opposition parties will not have to worry about the Brexit Party cannibalising their vote. However, crucially, Farage ruled out standing down his candidates in the Labour-held ‘Red Wall’ which, as I explain in this video, is a crucial area to watch at this election. What impact will all of this have on the election? At first sight the announcement looks like a ‘game changer’, with the potential to weaken Labour and boost the Conservatives. But is it? Let’s return for a minute to the 2015 general election. Four years ago, UKIP, the predecessor of the Brexit Party, presented a much bigger challenge to the two major parties than the Brexit Party’s 8 per cent voteshare does now. Back then, UKIP took an average of just over 14 per cent of the constituency voteshare in England and almost the same in Wales. If the Brexit Party is a threat to Labour in the present contest, UKIP was much more so in 2015. The chart below shows the relationship between the vote for Labour and UKIP in the 573 seats in England and Wales in 2015. The summary line shows that a larger Labour vote was associated with a smaller UKIP vote. In other words, Labour succeeded in fending off the UKIP challenge in its safe seats. To be fair, the relationship between these vote shares was fairly weak (a correlation of only -0.13) but it was nonetheless true that UKIP did not break through in safe Labour seats. Labour and UKIP vote in England and Wales in 2015 But this overall picture masks to some extent what happened in the North and Midlands, regions where today Boris Johnson and the Conservatives will have to win seats off Labour if they are to get an overall majority. So, we need to drill down a bit. In 2015, Labour won a total of 149 seats across the North East, North West, the Midlands and in Yorkshire and Humberside. In 48 of them, the combined UKIP and Conservative voteshares were greater than that of Labour. Examples include Blackpool South, Chester, Coventry North West and Darlington. It is a fair bet, then, that had Farage and UKIP not stood in these seats then the Conservatives would have won a good number of them, and this would have delivered a bigger working majority than Cameron’s more limited majority of only twelve MPs. The Conservatives took 329 seats in the 2015 election, but only 63 had a combined Labour and UKIP vote share greater than the Conservative vote. A survey of voters at the time revealed that for every vote UKIP took off Labour, it took three off the Conservatives. So, if UKIP had stood down in Conservative seats in 2015, UKIP voters would have switched to Cameron rather than Ed Miliband, and Labour would have gained few seats. The same is true now. If the Brexit Party had stood down in Labour-held seats, this would probably have delivered a majority to Boris Johnson, and would certainly have been far more helpful to him than standing down in existing Conservative territory. Consider just a few stats: there are already 10 Labour-held seats where even the weaker UKIP vote in 2017 is greater than the current Labour majority. Throw much of this vote to the Conservatives and these seats will likely fall to the Conservatives. But what happens if the Brexit Party attracts just a few percentage points in the 20 Labour-held seats that have a majority of less than 2 points and the 31 Labour-held seats that have a majority of less than 5 points? It is not hard at all to see how Nigel Farage could yet throw a big spanner in the works for Johnson. The Brexit party’s tacit recognition that the Conservatives are the only credible Leave party also draws attention to the fact that Labour is the only credible Remain party. This is of course bad news for the tactical alliance between the Liberal Democrats, Greens and Plaid Cymru. Volatility is still high, so if the Conservatives remain 10 points ahead of Labour on polling day, they are likely to win a majority. If this happens, then Nigel Farage will no doubt claim credit for it – but it is a dubious claim in reality.