BORIS Johnson has received a massive boost in his bid for power after Nigel Farage said the Brexit Party would not contest Tory-held seats after the Prime Minister’s promises on Brexit but concentrate its “total effort” on Labour-held ones.

The announcement means, in wake of the Remain Alliance between the Liberal Democrats, the Greens and Plaid Cymru, there will also now be an effective Leave Alliance.

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At a campaign event in Hartlepool – an area that voted to Leave in the 2016 referendum - Mr Farage said his party would not fight the 317 Conservative seats the Tories won at the last election but would focus on fighting Labour in the ones they held.

He explained that he had considered overnight Mr Johnson’s comments that there would be no political alignment with the EU after Brexit and that the transition period would not be extended beyond December 2020.

Mr Farage told supporters: "I will tell you now exactly what we are going to do. The Brexit Party will not contest the 317 seats the Conservatives won at the last election.

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"But what we will do is concentrate our total effort into all the seats that are held by the Labour Party, who have completely broken their manifesto pledge in 2017 to respect the result of the referendum.

"And we will also take on the rest of the Remainer parties. We will stand up and we will fight them all," he declared.