Theresa May has accused the SNP of treating people’s lives as a “game” and urged Nicola Sturgeon to throw off her “tunnel vision” on independence.
The prime minister said she believed “passionately” in the UK which she described as the “most successful political union the world has ever seen”.
And she insisted people in Scotland wanted a government focused on the “issues that matter to them day to day”.
In a wide-ranging interview with the Press and Journal, Mrs May also voiced her support for the “world class” North Sea oil and gas industry and said her party would “fight hard” across Scotland in the summer’s local elections.
Her intervention, on the eve of her speech to the Scottish Conservatives conference in Glasgow, came as new research emerged showing fewer than a third of Tory activists believe the loss of Scotland would cause serious damage to the rest of the UK.
The study, conducted by the Centre for English Identity and Politics at Winchester University, also revealed more than two thirds would not want the prime minister to offer any new financial or policy powers to the Scottish Government in the event of a second referendum.
Asked if she thought devolution had gone far enough or even too far, Mrs May simply insisted the UK was “stronger together”.
She said: “The way I look at it is I believe absolutely passionately in the union. It is a very precious bond that we have.
“It has been the most successful political union actually that the world has seen.
“But if we look at this question of independence for the future, I also think this – to me politics isn’t a game.
“Politics is about how we as politicians deliver for people in their day to day lives.
“I think that the SNP often treat politics as a game. I think they have tunnel vision on this issue.
“They only seem to be looking at independence, whereas I think people in Scotland don’t want a second referendum.
“I think what they want is for the SNP Government to concentrate on the issues that matter to them day to day, like the state of education, what’s happening in the NHS, the state of the Scottish economy.
“They want the SNP Government to get on with the day job and stop this tunnel vision of only focusing on independence.”
As the prime minister headed north, Nicola Sturgeon again warned the UK Government against using Brexit to “undermine” devolution with a cash and power grab.
The first minister also claimed the Tories had no intention of handing new powers to Holyrood and accused them of trying to “muscle-in” on those it already has.
Responding ahead of Mrs May’s visit, she added: “The Scottish Government’s approach since the EU referendum has been to offer compromise and to seek consensus at every turn – in return the UK Government’s has so far been one of obstinacy and intransigence.
“If the prime minister thinks she can come to Scotland and sermonise about where power should lie, in the manner of one of her Tory predecessors, she should remember this – her government has no mandate in Scotland, and no democratic basis to take us out of Europe and the single market against our will.
“But increasingly, this Tory Government seems to think it can do what it wants to Scotland and get away with it.”
Frank McAveety, the Labour leader of Glasgow City Council, said his party would continue to oppose a “hard Tory Brexit”.
He added: “We will fight against SNP plans for a second independence referendum that would be even more damaging for jobs and businesses.
“While Theresa May and Nicola Sturgeon are both obsessed with sowing division, Scottish Labour believes that our country is divided enough and that together we’re stronger.”