May accused of 'losing UK momentum' with new delay
The British Prime Minister was expected to formally start negotiations with other EU member states as early as this week once parliament had passed a law allowing talks to begin.
However, Mrs May is understood to be targeting triggering Article 50 on Wednesday March 29, after a speaking tour of Britain when she will sell her vision for the UK outside the EU.
This delay has led to concerns that Mrs May now cannot begin formal talks until May, missing the chance of talks with EU leaders on April 6.
Lord Jones, of Birmingham, a cross-bench peer who was a trade minister in the last Labour government, said he "cannot understand why she has done it". The peer, who was head of the Confederation of British Industry for eight years, praised Mrs May for the way she has "handled" the period leading up to the start of negotiations.
But he said: "If she has delayed it by two weeks, I am disappointed; it is an error." She was now in danger of "losing momentum".
Other MPs urged Mrs May to trigger Article 50 to avoid the chance of another legal challenge to the process being made to the High Court.
Bill Cash, the euro-sceptic Tory chairman of the EU scrutiny committee, said it was "essential that ministers take the best possible legal advice and act as quickly as possible. Getting the Article 50 letter out is an absolute priority".
Former Ukip leader Nigel Farage added that he was worried the start of talks had been "kicked into the long grass in May". He said: "Now that we are delaying the triggering of Article 50, what it means is that we will miss the summit of European leaders on April 6 at which Brexit could practicably have been discussed."
Senior government figures admitted talks will not get under way properly in April because of the long parliamentary recess and Easter.
But the source denied that the delay would damage Britain's interests because preliminary talks had been going on "for weeks" between the UK and EU. This is despite EU leaders insisting that Brexit talks cannot begin formally until Article 50 of the Lisbon Treaty has been triggered.
One said: "Despite the fact that they say there is no negotiating there is contact going on with the commission.
Gina Miller, the fund manager whose legal challenge forced the government to legislate for the start of Brexit talks, threatened more legal action if MPs and peers were not given a proper vote on the final package.
"If they don't deliver on that I will take them back to court," she said.
A spokesman for Mrs May played down suggestions of a delay due to the announcement by Ms Sturgeon saying she had always said she would trigger Article 50 by the end of March.