THERESA MAY has hailed the agreement by EU leaders to give the green light for the second phase of Brexit talks to begin as an “important step” on the road to a “smooth and orderly” withdrawal.

The move was agreed in a meeting of the leaders of the 27 remaining EU states lasting less than half an hour in Brussels, in the Prime Minister’s absence.

Guidelines agreed at the European Council summit revealed the EU expects Britain to remain under the jurisdiction of the European Court of Justice and permit freedom of movement during a transition period expected to last two years after the official date of Brexit in March 2019.

European Council president Donald Tusk announced the decision on Twitter: “EU leaders agree to move on to the second phase of #Brexit talks. Congratulations PM @theresa_may.”

Mrs May said: “This is an important step on the road to delivering the smooth and orderly Brexit that people voted for. The UK and the EU have shown what can be achieved by commitment and perseverance on both sides.

“I am pleased it has been agreed that we should make rapid progress on an implementation period, which will give certainty to businesses and to individuals. There is still more to do but we are well on the road to delivering a Brexit that will make Britain strong, prosperous and secure.”

Mrs May said talks on Britain’s future relationship with the EU would begin “straight away”.

“We will set up and negotiate a new trade deal with the European Union but also we will be negotiating trade deals with countries around the world,” she said.

Mrs May’s hopes of avoiding a second Commons defeat over Brexit also improved after senior Tory backbenchers from both the Leave and Remain factions appeared to be ready to back a compromise over the Prime Minister’s plan to write the date the UK leaves the European Union into law.

A second humiliating Commons reverse now appears less likely as a compromise amendment tabled by senior MPs including Sir Oliver Letwin and Bernard Jenkin appeared to win over would-be rebels.

The Government is understood to be looking closely at the amendment, which would give ministers flexibility to change the day through regulations if MPs agree.

East Renfrewshire Tory MP Paul Masterton, a potential Tory rebel who abstained in the defeat on Wednesday, said it was a “sensible amendment to the Withdrawal Bill that gives us flexibility on Brexit date if we need”.

The ringleader of Wednesday’s revolt, Dominic Grieve, told the BBC the amendment would leave him “fairly satisfied”.

Earlier, a efforts to achieve a compromise intensified, Tory Chief Whip Julian Smith sent a cryptic tweet of an image of a telephone with a reference to Prince Harry and Meghan Markle’s wedding and the message “great news and great example - agreeing the date shouldn’t be hard”.

Earlier in the day, Mr Tusk warned it would be “dramatically difficult” to get both a withdrawal deal and an agreement on a future trade relationship done by Brexit day on March 29, 2019.

“For sure, the second phase will be more demanding, more challenging than the first phase,” he said.

Before leaving Brussels, Mrs May won applause from the other leaders as she assured them over dinner on Thursday evening of her determination to see Brexit through despite the Commons defeat.

During the transition period, the UK will be required to follow the EU rule book in its entirety – including laws adopted during the transition period – while playing no part in European decision-making.

The guidelines said Britain will be expected to observe the single market’s “four freedoms” of movement of goods, services, people and capital during the period.

During the transition, the guidelines state, “all existing Union regulatory, budgetary, supervisory, judiciary and enforcement instruments and structures will ... apply, including the competence of the Court of Justice of the European Union.”

In a blow to the Brexiteers’ hopes of moving quickly to detailed trade talks, it emerged the agreement on a trade relationship can only be finalised once the UK has left the EU.