Rishi Sunak has said Nicola Sturgeon needs to be beaten rather than ignored, aiming a dig at Liz Truss who earlier this week called Scotland’s first minister an “attention seeker”.

Mr Sunak said Ms Sturgeon and her party the SNP “pose an existential threat to our cherished union”, adding: “Arguing that we should ignore them is dangerously complacent.”

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“We can’t just bury our heads in the sand and pretend they aren’t there – we need to stop them in their tracks,” the former chancellor said.

“And that’s exactly what I would do as prime minister – holding the SNP to account for its failings and personally ensuring that the UK government has a laser focus on delivering for every part of our United Kingdom.”

It comes a few days after Tory leadership frontrunner Ms Truss suggested she would “ignore” Ms Sturgeon if she were to become the next leader of the Conservative Party.

Speaking at a Tory leadership hustings in Exeter, the foreign secretary called Scotland’s first minister an “attention seeker” and responded “no, no, no” when asked about the prospect of another independence referendum if she were to become PM.

“I really believe we are a family, and we’re better together,” she said.

“I think the best thing to do with Nicola Sturgeon is ignore her. She’s an attention seeker, that’s what she is.”

But the SNP hit back at the “cack-handed” comments, saying they would only boost support for independence.

The party’s deputy leader in Westminster, Kirsten Oswald, said: “The likely next prime minister has made crystal clear the partnership of equals Scotland was promised in 2014 was a sham.

“Firing cheap shots to grab headlines is straight out of the Trump playbook but reveals as never before the contempt Westminster has for the democratic choices people in Scotland make and the elected Scottish government.”

On Friday evening, Ms Sturgeon herself acknowledged the remark, tweeting a picture of a seal captioned: “Spotted this cute seal in beautiful Argyll. I think s/he might be a bit of an attention seeker.”

Some Tory MPs also criticised Ms Truss‘ remarks, with former minister Liam Fox saying Ms Sturgeon had to be “treated with respect”.

Mr Fox, who is backing Mr Sunak in the leadership contest, told Sky News: “Whenever I hear politicians accusing other politicians of being attention seeking, I do tend to raise an eyebrow.

“When it comes to the first minister of Scotland, they have a constitutional position, they have to be treated with respect.”

Both Mr Sunak and Ms Truss have been clear that they would not grant Ms Sturgeon a second independence referendum in Scotland if elected as PM and would instead seek to strengthen the union.

Meanwhile, Mr Sunak has also accused Ms Truss of “imitation” as the foreign secretary is set to reveal her levelling up plan which has been backed by regional Tory leaders.

The foreign secretary is expected to announce that she will review the levelling up formula to fix underinvestment in regional infrastructure if she becomes prime minister and will ensure transport links are better integrated across buses, road, and rail.

Ms Truss will add that her administration would make the most of the UK’s “new Brexit freedoms” – including creating low tax, low regulation “investment zones” on brownfield sites.

Ahead of unveiling her levelling up proposals at the Commonwealth Games in Birmingham on Saturday, Ms Truss said: “My mission as prime minister will be to level up opportunity and realise aspiration no matter who you are or where you live.”

But Mr Sunak’s team accused Ms Truss of “copy and pasting policies put in place by Rishi” and “re-announcing two-year-old government policies”.

“Imitation is the best form of flattery, as the saying goes,” they said.

However, regional Tory leaders Andy Street, mayor of the West Midlands and Jake Berry, chair of the Northern Research Group described Ms Truss’ levelling up initiatives as a “bold vision”.

Mr Street said: “She has a bold vision for our regional economies, with the policies we need to make levelling up a reality. Her plan for investment zones, for instance, will give us a powerful tool for unlocking new investment, jobs, and growth.”