Liz Truss has vowed to "face down" the SNP over its attempts to rip apart the United Kingdom, as she accused Nicola Sturgeon of being part of an "anti-growth coalition".
The Prime Minister told the Tory conference that the UK was "at its best" when the home nations are "working together and getting our economy growing".
Speaking ahead of the SNP conference in Aberdeen and next week's Supreme Court hearing on Ms Sturgeon holding a legal independence referendum, she vowed to defeat the "the separatists who threaten to pull apart our precious Union".
Ms Truss offered to work with Ms Sturgeon to create investment zones in Scotland, which she argued would boost Scotland's sluggish economic growth rates by cutting taxes and red tape.
But she argued that the First Minister was part of a coalition of naysayers, along with Sir Keir Starmer, the Labour leader, and Mark Drakeford, her Welsh counterpart, who "don't understand aspiration" and are content to let taxes rise.
The Prime Minister cited Ms Sturgeon's decision to block the construction of new nuclear power stations to "solve the energy crisis in Scotland".
Even though SNP ministers have repeatedly claimed that Scotland generates more than enough power from renewable sources, particularly wind, it still relies heavily on gas and nuclear when the wind is not blowing.
In a scathing response on social media, Ms Sturgeon said:
Ranting about an imaginary ‘anti growth coalition’ is just an attempt to obscure the hard reality that the biggest brake on UK growth is Brexit - and that’s on the Tories.
— Nicola Sturgeon (@NicolaSturgeon) October 5, 2022
But Scotland's GDP has grown at less than half the UK rate since 2014. On Wednesday, economists predicted that the country will enter recession in the second half of this year.
The University of Strathclyde's Fraser of Allander Institute predicted that the Scottish economy will contract in the final two quarters of 2022 and the first quarter of 2023. A recession is defined as two successive quarters of negative growth.
In a significant downward revision from its June forecasts, the institute predicted the Scottish economy will grow by 3.6 per cent this year, followed by a 0.6 per cent contraction in 2023 - before returning to 0.8 per cent growth the following year.
Ms Truss used her keynote address to the Tory conference in Birmingham to describe how she had seen "boarded-up shops", people turning to drugs and families struggling to put food on the table during her upbringing in Paisley and Leeds.
Arguing this was a direct result of low growth, she outlined her plans for investment zones, saying: "Now is the time to harness the power of free enterprise to transform our country and ensure our greatest days lie ahead.
"This is the United Kingdom at its best, working together and getting our economy growing. And we will face down the separatists who threaten to pull apart our precious Union, our family."
Kwasi Kwarteng, the Chancellor, used his controversial mini-Budget to cut the basic rate of income tax in England from 20p to 19p from next April, further widening the tax gap with Scotland.
A Scot earning £50,000 per year already pays almost £1,500 per year more income tax than someone on the same salary living in England. However, this gap is on course to swell to £1,863, unless Ms Sturgeon takes action.
On Wednesday, Holyrood's finance committee asked John Swinney, the Deputy First Minister, to publish the Scottish Budget on Dec 15, setting out any income tax changes. The Treasury has handed him hundreds of millions of pounds that could be used to replicate the cuts in England.
Ian Blackford, the SNP's Westminster leader, said: "Liz Truss has been a disaster for Scotland - and this arrogant speech demonstrates why Scotland needs independence to escape Westminster control and get rid of the Tories for good."