Theresa May set to deliver her 12-point Brexit plan

Prime Minister Theresa May will give further details of her plans for leaving the European Union in a key speech on Tuesday.

Extracts released by 10 Downing Street suggest Mrs May will set out her 12 negotiating objectives and say the UK will not settle for a "half-in, half-out" policy, fueling speculation Britain will leave the single market and customs union.

The Prime Minister will say she wants a "truly global Britain" which will be "more outward-looking than ever before" and will remain "the best friend and neighbour" of the other 27 members of the EU.

However she will also insist her government will not seek "to adopt a model already enjoyed by other countries... [or] hold on to bits of membership", or achieve a "partial" or "associate" membership of the EU.

Theresa May will say her Brexit strategy will be provide certainty and clarity. Credit: PA

The Prime Minister will also set out her four "simple principles" that will help drive the negotiating process.

They will be:

  • Certainty and clarity

  • A stronger Britain

  • A fairer Britain

  • A truly global Britain

The value of the pound has slumped ahead of the speech. Credit: PA

The pound fell below $1.20 on the eve of the address, with Bank of England governor Mark Carney warning of further market volatility as nervous traders weigh up the possible impact of Mrs May's statement.

Downing Street said the Prime Minster will deliver her negotiating priorities for the upcoming EU withdrawal talks, but stopped short in suggesting what those could be.

According to the Telegraph, she will make regaining control of Britain's borders one of her central themes.

It is expected Mrs May will say: "I want this United Kingdom to emerge from this period of change stronger, fairer, more united and more outward-looking than ever before.

The Prime Minster will insist that Britain is leaving the European Union. Credit: PA

"I want us to be a secure, prosperous, tolerant country - a magnet for international talent and a home to the pioneers and innovators who will shape the world ahead.

"I want us to be a truly Global Britain - the best friend and neighbour to our European partners, but a country that reaches beyond the borders of Europe too. A country that gets out into the world to build relationships with old friends and new allies alike.

"I want Britain to be what we have the potential and ambition to be: a great, global trading nation that is respected around the world and strong, confident and united at home."

Many high-profile international meetings have taken place at Lancaster House, London. Credit: PA

The Prime Minister will deliver her speech in front of diplomats from otherEU states at Lancaster House in London.

The venue was chosen because of its history as "part of Britain's engagement with the world".

It will come less than 11 weeks before her end-of-March deadline to trigger Article 50.