LONDON, March 16 (Xinhua) -- A war of words over Scottish independence erupted Thursday after Britain's prime minister ruled out an early referendum.

Scotland's first minister, Nicola Sturgeon, leader of the Scottish Nationalist Party (SNP) said in a statement in Edinburgh that it would be a democratic outrage if Theresa May tried to block the people of Scotland from having a choice over their future destiny.

Earlier this week, Sturgeon announced she plans to ask the Scottish Parliament next week to back her call for a new referendum to decide if Scotland should remain as part of Britain. The people of Scotland in 2014 voted to remain in the EU by a large margin.

Sturgeon wants a new referendum next year or early 2019, saying Britain's decision to leave the EU changes the situation for Scotland which voted remain last June.

May said she was opposed to a second independence referendum while Brexit talks with Brussels were continuing.

Though May did not comment on or rule out a second referendum in Scotland at some future date, she said now is not the time for a referendum and instead Scotland should work with the government to seek the best deal with the EU for Scotland and the rest of Britain.

May's statement drew am angry response from Sturgeon. In a statement she said: "We are not proposing a referendum now. We are proposing to give the people of Scotland a choice once Brexit is clear but before it is too late. We will put our proposition to the Scottish Parliament next week and then we will put our formal proposals to the UK government."

"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. It would be outrageous for the Scottish Parliament to be frozen out of the process," she added.

Former SNP leader Alex Salmond, now a Westminster MP, described May's action as a miscalculation, stating: "This finger-wagging at Scotland, this Theresa May laying down the law, it's not going to work."

The Labour Party in Scotland said it would vote against a second independence referendum.

Earlier on Thursday, Queen Elizabeth II gave royal assent to May's Brexit bill giving the prime minister official authority to trigger the Article 50 process to signal the start of Britain's exit from the EU.

Brexit Secretary David 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 neighbors in the European Union, as well as taking a step out into the world as a truly global Britain."