Brexit: UK 'lying flat on the canvas', Boris Johnson says in blistering attack on Theresa May's Chequers plan

'The fix is in. The whole thing is about as pre-ordained as a bout between Giant Haystacks and Big Daddy,' former foreign secretary writes

Theresa May's hopes of persuading Tory MPs to back her Brexit strategy have been dealt a further blow after Boris Johnson launched a barbed attack on the plan, saying it has left the UK "lying flat on the canvas".

The former foreign secretary called the prime minister's Chequers deal a "fix" and said it would not deliver Brexit.

Mr Johnson, who resigned from the cabinet over the plan, also accused some members of the cabinet of trying to "stop a proper Brexit" by using the problem of the Northern Ireland border to keep Britain closely tied to the European Union.

His latest intervention is a sign of Tory Eurosceptics' growing opposition to the Chequers proposals, and came as more than 20 Conservative MPs pledged to vote down the plan

It is also likely to fuel speculation that Mr Johnson is stepping up his bid to replace Ms May as a prime minister.

Writing for the Daily Telegraph, the Uxbridge and South Ruislip MP compared EU negotiations to a rigged wrestling match and said the UK was "lying flat on the canvas".

He wrote: "The fix is in. The whole thing is about as pre-ordained as a bout between Giant Haystacks and Big Daddy; and in this case, I am afraid, the inevitable outcome is victory for the EU, with the UK lying flat on the canvas with 12 stars circling symbolically over our semi-conscious heads".

He added: "The reality is that the EU has so far taken every important trick. The UK has agreed to hand over £40bn of taxpayers' money for two thirds of diddly squat."

Tory Brexiteers have complained that the Chequers plan would keep Britain tied too closely to the EU, because it would invole the UK adopting a "common rule book" for goods and collecting tariffs on behalf of the bloc.

Those proposals were developed as a way of maintaining an open border between Northern Ireland and the Republic of Ireland when UK leaves the EU, including the single market and customs union, next March.

However, Mr Johnson said the border had been "ingeniously manipulated" by some members of the government to block Brexit.

He wrote: "It is now clear that some in the UK government never wanted solutions. They wanted to use that problem to stop a proper Brexit.

"Solving Ireland would mean a solution for Dover-Calais, and they didn't really want that. They wanted essentially to stay in, and to create a Brexit in name only. They have been rumbled. People can see Chequers means disaster."

Of the Northern Ireland border issue, he said: "It is fixable. The scandal is not that we have failed, but that we have not even tried."

Mr Johnson said the Chequers plan amounted to having "gone into battle with the white flag fluttering over our leading tank" and would mean "abandoning the notion of the UK as a proud, independent economic actor."

He said: "We will remain in the EU taxi; but this time locked in the boot, with absolutely no say on the destination. We won’t have taken back control – we will have lost control.”

His comments were criticised by Tory MP Nick Boles, who said he also opposed Ms May's strategy but called Mr Johnson's claims "unfair and a bit derogatory".

He said: "This is not the time to start monkeying around changing leader.

"This is the first time I have broken with my Prime Minister but she is wrong on this.

"She has not succeeded, let's be clear, but we have a prime minister and I want her to deliver a better Brexit - the kind of Brexit I have set out in my plan."

Mr Johnson's intervention comes as Ms May faces growing opposition from her own MPs to the Chequers plan, raising the prospect that her Brexit deal could be voted down by MPs.

As MPs prepare to return to Westminster after their summer break, 20 Tory backbenchers publicly backed a campaign to scupper the proposals.

Former ministers including Priti Patel and Iain Duncan Smith have joined the StandUp4Brexit group, which is fighting Ms May's plan.

Former Brexit secretary David Davis, who also quit in protest at the Chequers deal, said yesterday that he would vote against the plan, which he described as "actually almost worse than being in " the EU.

Brexiteers are reported to be working alongside David Cameron's former elections guru Sir Lynton Crosby, in a bid to ensure the proposals are ripped up.