Theresa May will set out a 12-point plan for Brexit as she vows that the UK will not have “partial” membership of the EU “that leaves us half-in, half-out”.

Mrs May will make her most significant speech since becoming Prime Minister in July last year and confirm that Britain will leave the single market and customs union after Brexit.

In remarks that will delight Conservative Eurosceptics, Mrs May will pledge that Britain outside the European Union will be a “great, global trading nation” that is “respected around the world and strong, confident and united at home”.

The Prime Minister will make regaining control of Britain’s borders one of the central themes of her Brexit strategy and will also make clear that the rights of UK expats will be protected.

She will make clear for the first time that Britain will not seek a watered down version of Brexit, something that Remain campaigners are still pushing for.