Refusal by British Prime Minister Theresa May to discuss an independence referendum would "shatter beyond repair" the United Kingdom's constitutional structure, Nicola Sturgeon has told the Scottish National Party.
Ms Sturgeon pledged to press on with plans to hold a new Scottish referendum as announced earlier this week, deepening a standoff with the UK government.
Party faithful gave her a rapturous reception, cheering, clapping and jumping to their feet.
Ms Sturgeon expects to get authorisation from the devolved Scottish parliament on Wednesday to seek the terms for a new secession vote, aiming for a date once the terms for Brexit are clear but before Britain leaves the EU.
"To stand in defiance of (Scottish parliamentary authorisation) would be for the prime minister to shatter beyond repair any notion of the UK as a respectful partnership of equals," Ms Sturgeon, who is also Scotland's First Minister, said.
"Scotland's future will be in Scotland's hands."
Under the UK's constitutional arrangements, Britain's parliament needs to sign off on any legally binding vote in Scotland.
Prime Minister Theresa May told Ms Sturgeon this week that "now is not the time" for a new choice on independence as divorce talks for the world's fifth-largest economy with its erstwhile EU partners get under way.
Although Ms May did not deny a vote outright, Scottish nationalists predict her words could build support for secession because it will look like she is telling Scotland what to do.
"[Ms May] has time to think again and I hope she does. If her concern is timing then - within reason - I am happy to have that discussion," Ms Sturgeon said.
The two sides are in a standoff just days before Britain is expected to trigger Article 50 of the EU's Lisbon Treaty and start the complex Brexit procedure.
Last June's vote to leave the EU has altered the political landscape and shaken the ties of the United Kingdom's four nations. England, the UK's most populous nation, and Wales voted to leave while the Scots and the Northern Irish wanted to keep their EU membership.
Scottish nationalists say the UK government has all but ignored their proposals of a bespoke deal for Scotland within Brexit.
"If [Ms May] shows the same condescension and inflexibility, the same tin ear, to other EU countries as she has to Scotland then the Brexit process will hit the rocks," Ms Sturgeon said.