British Prime Minister Theresa May rejected a call for a referendum on Scottish independence before Britain leaves the EU - a move condemned as a "democratic outrage".
Mrs May said "now is not the time" to reopen Scotland's independence debate, though she did not rule out a referendum in the future.
Scottish First Minister Nicola Sturgeon said it would be a "democratic outrage" for the British government to stop the people of Scotland from "having a choice over their future".
"It is for the Scottish parliament - not Downing Street - to determine the timing of a referendum, and the decision of the Scottish parliament must be respected," she said.
Still, Mrs Sturgeon's Scottish National Party does not hold an outright majority in the Scottish legislature.
It came after the Queen signed the Article 50 Bill into law, giving Mrs May the power to start Brexit negotiations.
Brexit Secretary David Davis said Mrs May would formally invoke Article 50 by the end of March, allowing the UK to start talks on creating a "positive new partnership" with the EU.
"The Queen has today given royal assent to the Article 50 Bill, giving the government the formal power to trigger Article 50 and deliver on the will of the British people," Mr Davis said.
"By the end of the month we will invoke Article 50, allowing us to start our negotiations to build a positive new partnership with our friends and neighbours in the European Union, as well as taking a step out into the world as a truly global Britain."
Britain's future trading relationship with the bloc and any exit bill which it may have to pay are both set to be highly contentious issues in the forthcoming negotiations.