Theresa May has insisted she will not be quitting as Prime Minister anytime soon, amid deep divisions in her party over Brexit.

Asked on Tuesday morning how long she could remain as party leader, May said: “I’m in this for the long term, not just for the Brexit deal but actually for the domestic agenda we are setting out at this conference.”

The Conservative Party conference in Birmingham this week has been dominated by demands from all sides that the PM abandon her controversial Chequers plan, which details proposals for the UK’s exit from the EU.  

Pressure is mounting ahead of a rally this afternoon to be held by the former Foreign Secretary, Boris Johnson, who arrives in town to address more than 1,000 supporters on the fringes of the event.

Johnson will warn May to not “ape” Labour leader Jeremy Corbyn as he sets out what will be widely seen as a leadership agenda. He will tell party activists he wants to slash taxes, crack down harder on crime and build more houses.

“We can’t lose our faith in competition and choice and markets but we should restate the truth that there is simply no other system that is so miraculously successful in satisfying human wants and needs,” he will say.

Senior Conservatives have hit back at Johnson for his attacks on the government. Chancellor Philip Hammond yesterday said his former cabinet colleague would never be prime minister and mocked him for not being capable of “grown-up politics”.

Former CBI chief Digby Jones won applause on Sunday when he said Johnson’s criticisms of businesses “showed him up for the irrelevance and offensive person he is”.

Downing Street tried to get ahead of Johnson’s speech this morning by announcing details of the government’s plan for immigration post-Brexit.

Under the scheme, high-skilled workers will be given preferential treatment once Britain quits the EU.

The Prime Minister confirmed that European Union countries will be treated the same as those across the rest of the world.