Boris Johnson has delivered a further damning indictment of Theresa May's plans for Brexit, accusing the the Chequers deal of "abandoning control".
Writing in the Daily Telegraph, the former foreign secretary warned that Brexit negotiations were approaching a critical phase and urged Downing Street to "chuck Chequers".
Under the title "A better plan for Brexit", Mr Johnson said the government needed to show the "guts" to deliver on the UK's vote to leave the EU - and called for a "super Canada" free trade deal.
Mrs May has repeatedly played down the prospects of a Canada-style agreement, arguing that it risks breaking up the UK.
Ex-mayor of London Mr Johnson, who has been criticised for not offering a clear plan on Brexit, attempted in the article to set out his manifesto.
In his article, Mr Johnson said that Mrs May should rip up her Brexit "backstop" agreement with the EU and negotiate a Canada-style free trade deal to "fulfil the instruction of the people".
Mr Johnson likened Chequers to a "moral and intellectual humiliation" which will "cheat the electorate", adding that it would leave Britain "half in, half out" of Europe.
"The Chequers proposals are deservedly unpopular with the UK electorate and have at least formally been rejected by our EU friends," Mr Johnson wrote.
He continued: "Overall, the Chequers proposals represent the intellectual error of believing that we can be half-in, half-out: that it is somehow safer and easier for large parts of our national life to remain governed by the EU even though we are no longer in the EU."
Mr Johnson added: "The Chequers proposals are the worst of both worlds. They are a moral and intellectual humiliation for this country.
"It is almost incredible that after two years this should be the opening bid of the British government."
Mr Johnson said that Britain had to accept that it might not be able to negotiate a suitable Brexit deal by March 2019, or a Canada-style free trade agreement by 2020.
He also said that the government needed to "accelerate" preparations for no deal being agreed with the EU.
He wrote: "The world is watching the UK, and it would be fair to say that our audience has been mystified and dismayed.
"Our partners around the world want us to take advantage of Brexit. They want a UK that is rich and strong and free.
"They cannot understand why we would want – after Brexit - to stay locked in the orbit of the EU.
"This is the moment to change the course of the negotiations and do justice to the ambitions and potential of Brexit."