Article 50 will not be activated this week, Downing Street has revealed.
Whitehall civil servants had been told to prepare for the triggering of the formal mechanism to withdraw the UK from the European Union as early as Tuesday.
But a spokesman for Theresa May said the Article 50 process would now not be initiated until next week at the earliest.
Asked if the Prime Minister intended to trigger Article 50 tomorrow, her spokesman said: "We have been clear. The Prime Minister will trigger Article 50 by the end of March."
It had been rumoured that the Article 50 bill would be passed by the Commons on Monday night and receive royal ascent on Tuesday morning, in time for the Prime Minister to formally give notification to Brussels the same day, but Downing Street has dismissed such speculation.
Her spokesman said: "I've said end many times but it would seem I didn't put it in capital letters quite strongly enough."
It is now thought that the most likely date for the historic move will be in the last week of March, following the special summit of the remaining 27 member states in Rome on March 25 to mark the 60th anniversary of the European Union.
It comes after SNP leader Nicola Sturgeon announced plans to call for a second referendum on Scotland's independence.
The Scottish First Minister said on Monday morning that a second poll would give Scotland a choice between Ms May's Brexit deal and remaining in the EU as an independent country.
Responding to that statement, the Prime Minister said: "The tunnel vision that the SNP has shown today is deeply regrettable. It sets Scotland on a course for more uncertainty and division, creating huge uncertainty," the PM said.
"This is at a time when the Scottish people, the majority of the Scottish people, do not want a second independence referendum.
"Instead of playing politics with the future of our country the Scottish government should focus on delivering good government and public services for the people of Scotland. Politics is not a game."
The 30-strong Conservative Group for Europe (CGE) accused the PM of appearing to be “asking for the wrong things, in the wrong way and on the wrong timescale”.