Theresa May has warned that independence would "wrench Scotland out of its biggest market" as she vowed that all four nations of the UK will leave the European Union as "one United Kingdom".
Opening the Scottish Conservative conference in Glasgow on Friday morning, the prime minister accused the Scottish government of "stoking up endless constitutional grievance" at the expense of governing the country.
The SNP's deputy leader, Angus Robertson, said the prime minister was guilty of "mind-boggling hypocrisy" and that it was May's "hard Brexit" which was threatening the Scottish economy.
In a speech almost entirely devoted to criticising the SNP and making the case for the future of the UK, May said there was "no economic case" for Scottish independence.
However, while she said that preserving the Union was her "personal priority" as prime minister, she did not rule out the prospect of giving the Scottish government the power to hold another independence vote in the future.
"The SNP point out the importance of the European market to Scottish businesses," said May. "I agree – it is important. That’s why I'm determined to get the best possible access to it for Scottish firms as I am for Welsh, English, and Northern Irish firms.
"But what the SNP don’t point out is that the UK domestic market is worth four times more to Scottish firms. In fact, the EU comes third after the rest of the UK and the rest of the world as a market for Scottish goods.
"And yet the SNP propose Scottish independence, which would wrench Scotland out of its biggest market. They think independence is the answer to every question in every circumstance, regardless of fact and reality."
First minister Nicola Sturgeon has repeatedly raised the prospect of calling for another independence vote in the wake of the UK's vote to leave the EU, and is expected to move towards doing so at the SNP conference this month.
Sturgeon has called on May to consider her proposal to allow Scotland to remain a member of the European single market, and has warned that another referendum is "all but inevitable" if no such concessions are made.
However, May suggested during her speech that no special deal will be reached for Scotland and that all four nations of the UK will leave the EU together.
"I am determined to ensure that as we leave the EU, we do so as one United Kingdom, which prospers outside the EU as one United Kingdom," she told the Scottish Conservative conference.
"That means achieving a deal with the EU which works for all parts of the UK – England, Scotland, Wales, and Northern Ireland – and for the United Kingdom as a whole.
"When the UK government begins negotiations with the EU on Brexit, we will do so in the interests of all parts of the UK and of the UK as a whole. That is what I mean by governing for the whole United Kingdom."
The prime minister added that, despite a warning from Sturgeon this week that the Conservatives were launching an "attack on devolution", no powers will be taken away from the Scottish parliament after Brexit.
May pledged that more powers will be given to Holyrood when they're returned from Brussels but failed to name what those powers might be.
"While the SNP propose that decision-making should remain in Brussels, we will use the opportunity of Brexit to ensure that more decisions are devolved back into the hands of the Scottish people," said May.
Commenting on May’s speech, the SNP deputy leader Angus Robertson said the Scottish government has a "cast-iron mandate" for another independence referendum as it was laid out in its 2016 manifesto.
“This was an ironic, hypocritical and surreal speech from Theresa May, who before the EU referendum supported a campaign warning that leaving Europe would be a disaster, but is now determined to pull us over the cliff edge of an economically catastrophic hard Brexit," said Robertson.
“Theresa May is guilty of mind-boggling hypocrisy – it is her government’s constitutional obsession with a hard Brexit which is directly threatening Scottish jobs and livelihoods."