BORIS Johnson will today issue a thinly veiled ultimatum to Theresa May not to agree to follow any EU rules after Brexit.

In a major speech, the Foreign Secretary will brand having to comply with Brussels diktats as “undemocratic” and “intolerable”.

His intervention comes as the PM’s Brexit war cabinet is locked in a major showdown over how far and how quickly to diverge from the EU’s rulebook.

As The Sun revealed on Saturday, Mrs May has proposed a compromise blueprint to end her top table’s long running bitter fight over the dilemma.

Under her plan, the UK would align closely with Brussels on rules for manufactured goods to keep exports to Europe free flowing, but go our own way on other sectors like agriculture and services.

But making it clear that he will not put up with her middle way, Boris will say: “It is only by taking back control of our laws that UK firms and entrepreneurs will have the freedom to innovate, without the risk of having to comply with some directive devised by Brussels, at the urgings of some lobby group, with the aim of holding back a UK competitor.

“That would be intolerable, undemocratic, and would make it all but impossible for us to do serious free trade deals.”

Mr Johnson will add: “The British people should not have new laws affecting their everyday lives imposed from abroad, when they have no power to elect or remove those who make those laws.

“And there is no need for us to find ourselves in any such position.”

His hardline intervention heaps pressure on Mrs May, just a week ahead of a major away-day confrontation when the inner Cabinet meets at Chequers to finally decide the UK’s negotiating demands for a trade deal with the EU after months of dithering.

Boris will also today call on Britain to stop being the world’s “national self-deprecation” champion as he promises Brexit can fix the nation’s ills.

The Foreign Secretary also issues a sympathetic appeal to Remainers for unity in an exclusive article for The Sun.

Calling on the losing 48 per cent to end their 20 months of anger over the landmark referendum result, he pleads with them to see Brexit as “the great project of our age”, with “democracy and openness to the world” at its heart.

And Boris also tells Leavers that “must also reach out to those who still have anxieties”.

The UK will only reap the full opportunities of our EU exit if the whole country seizes the opportunity together.

He writes for Sun readers: “So much of this is about confidence and national self-belief.

“We Brits love to run ourselves down – in fact one of the many ways in which we lead the world is in the sport of national self-deprecation.

“But when the history books come to be written, Brexit will be seen as just the latest way in which the British bucked the trend, and took the initiative – and did something that responds to the real needs and opportunities of the world today.”

Nervous Downing Street aides have insisted on vetting at least two different drafts of Boris’s address – and were still in talks with him about the final text as late as today, The Sun can reveal.

Boris’s unity appeal was immediately rebuffed by some critics before he had even uttered a word.

Green leader Caroline Lucas said: “Boris is deluded if he thinks he of all people can ‘reach out to people who voted remain’.

“He lied to the public to further his own political goals – and people up and down the country are now picking up the pieces”.