Theresa May Signs Article 50 Letter to Trigger Brexit

Theresa May will strike a conciliatory tone as she invokes Article 50 this afternoon, offering a partnership with the rest of the European Union and imploring Britain to "come together".

The Prime Minister will formally launch the process for the UK to leave the European Union in a letter that will be hand delivered to European Council President Donald Tusk at around 12.30pm.

After marking out hard lines on future payments to the European Union and the influence of EU law after Brexit, the text of the Prime Minister's letter is expected to offer some room for manoeuvre in negotiations.

She will not comply with the wishes of her Brexiteer backbenchers who wanted to name the Article 50 date as a cut off for newly-arrived EU citizens to gain rights such as permanent residence.

Some Conservative MPs are concerned about a surge in the number of EU migrants.

However, on Tuesday the European Commission, Council and Parliament signalled that "EU law must apply until Brexit day" in two years' time.

The European Parliament, which can veto an UK-EU deal, is next week expected to make the guarantee of full EU citizen rights a red line.