The event had originally been due on Monday, but amid the chaos that followed the election, Downing Street refused to confirm when it would happen.

The Leader of the House of Commons Andrea Leadsom announced in Parliament that it will now take place on Wednesday next week, indicating that Ms May has sealed a deal with Northern Irish unionists to prop up her Government.

In a statement, Ms Leadsom said: The Government has agreed with Buckingham Palace that the State Opening of Parliament will take place on 21 June 2017.

The Queen’s Speech is effectively a list of all the laws that a government wants to pass over the course of a parliament and once it is read out by the monarch, is voted upon in the House of Commons.

Passing the vote is the most basic test of any administration’s credibility. But due to Ms May’s failure to secure a Tory majority, it was unclear the Conservatives could win the vote to enshrine her agenda in law.

That ministers have now confirmed the date, signals they believe they can win a vote, and therefore must have a solid pledge of support that the Northern Irish DUP MPs will back Ms May in the Commons.

The announcement also saves Ms May from the embarrassment of having to delay Brexit talks too much, after previously indicating they would also begin on June 19.

It would also have been humiliating for the Prime Minister to have to turn up to the European Council meeting on June 22 without having any legislative agenda for Brexit.