Theresa May has signalled that she will not quit if she loses next week’s key Commons vote on Brexit as leaked legal papers suggested that if the UK entered the so-called “backstop,” it would be difficult to strike trade deals with non-EU countries, including America.

Appearing on ITV’s This Morning, the Prime Minister pushed back after being asked if she would still be in No 10 should MPs reject her Brexit Plan next week, declaring: “I will still have a job in two weeks’ time.

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“And my job is making sure that we do what the public ask us to; we leave the EU but we do it in a way that’s good for them.”

HeraldScotland:

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Asked what would the UK Government would do if it were defeated – as seems likely on current parliamentary arithmetic - Mrs May once again refused to address the premise of the question and instead insisted she was "focused" on getting the legislation through.

"There’s going to be a lot of debate. There will be lots of quotes, there will be lots of things said about this in the next few days. When it actually comes to it, it’s a key moment of decision for MPs about what do we want to ensure when we leave the European Union," added the PM, who this afternoon will make a statement on the G20 summit in Argentina; although this will be dominated by questions about Brexit.

Denying the suggestion her agreement with Brussels was a "disaster," she said MPs would spend five days debating and dissecting it before the December 11 vote, stressing: "It is about holding our nerve and getting this over the line so we can deliver on Brexit and people can have that better future."

Asked if she felt “knackered” after a busy schedule trying to sell her deal to the public, Mrs May replied: “It’s a tough time, it’s a difficult time…an awful lot of work has had to go into this.

“But I always think the key thing is just keep focused on what the end-point is. The end-point is getting a good deal through for the UK and delivering on what people voted for.”

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Tomorrow, the PM will lead five days of Commons debate on various aspects of the UK-EU Brexit Plan with an opening statement. Later in the week, she is expected to resume her tour of the country with visits to different parts of England; last week, she visited Scotland, Wales and Northern Ireland.

At Westminster, a 27-page legal note prepared by the Commons EU legislation team was leaked just hours before Geoffrey Cox, the Attorney General, was due to deliver his own Commons statement and is expected to face numerous calls from MPs for the Government to publish the full legal advice on the PM’s Brexit Plan.

Pressed on whether Mr Cox would reveal this, No 10 simply said it would be a “full, reasoned position statement”.

The Commons legal note, marked “not for general distribution,” was written late last month and looks at the effects of the Withdrawal Agreement on UK law.

It says: “The customs union would be a practical barrier to the UK entering separate trade agreements on goods with third countries.”

The note appears to confirm Donald Trump’s view that the UK-EU Brexit deal might endanger signing a trade deal with the US.

Earlier on ITV’s Good Morning Britain, Tony Blair argued that any second Brexit referendum should be a choice between Remain and a hard Brexit.

The former PM claimed a second people's vote was the only way to settle the deadlock in Parliament.

"The only way to resolve this is to have the option Remain or Leave but leave on terms that make it clear this is hard Brexit.

"I honestly think if you're going to leave, leave, but don't do this halfway house," he added.

In a separate development, Sajid Javid admitted MPs were "very unlikely" to see plans for Britain's future immigration system before they voted on the Brexit Plan.

The Home Secretary has previously expressed his hope that the long-awaited White Paper would be published before December 11 but today said only that it would be published "soon".

He told BBC Radio 4's Today programme: "It's unlikely, actually very unlikely, to be published before the vote. It will be published soon."

Mr Javid and Chancellor Philip Hammond are reported to be pressing for the Government finally to abandon the target of reducing net migration below 100,000 a year; a move which Mrs May is said to be resisting.

Explaining the delay, Mr Javid said: "This is the biggest change in our immigration system in over four decades; the most significant change we're going to see in immigration as we take control of our immigration system, so it's important that we work on the details, that we listen to people, to businesses and others and we get the details right."

He said the new immigration system would be based on skills and not the nationality of people.

Ministers are planning to introduce new immigration rules that bring an end to free movement from 2021 after the end of the post-Brexit transition period.

Details of the proposed regime were initially due to be published as long as a year ago but they were held back while the independent Migration Advisory Committee carried out a detailed analysis, which was published in September.