Nicola Sturgeon has criticised Boris Johnson’s “absurd and ridiculous political comments” claiming there is no Scottish border, and urged him to focus on the coronavirus pandemic.

The First Minister said attempts to escalate a row about people potentially having to quarantine if entering Scotland from other parts of the UK are “frankly disgraceful”.

Ms Sturgeon has repeatedly stated she will not rule out such quarantine measures if they are supported by public health evidence, a suggestion the PM said he found “absolutely astonishing”.

At Prime Minister’s Questions on Wednesday, Mr Johnson said: “There have been no such discussions with the Scottish administration about that but I would point out to [Conservative MP Andrew Bowie] what he knows very well – there is no such thing as a border between England and Scotland.”

Asked at the Scottish Government’s coronavirus briefing about the comments, Ms Sturgeon said it was “such an absurd statement”, and added: “What there definitely is, is a geographical boundary to my powers as First Minister.

“If the Prime Minister is questioning that now, I’m not sure what he would say if I pitched up in Newcastle and started to try to implement Scottish Government policies in Newcastle.

If you find yourself trying to turn any of this into a political or a constitutional argument, go and take a long hard look at yourself in a mirror

“And see what I’ve just said there? It’s absurd too, which is why we shouldn’t be having these discussions.

“We should all be focusing with an absolute laser-like focus on what we need to do within our own responsibilities and working together when necessary to stop a virus.”

On the possibility of people having to quarantine after entering Scotland, Ms Sturgeon said there are no such proposals at the moment, but added: “Given the nature of what we’re dealing with right now – just to remind the Prime Minister: an infectious virus – I would not be doing my job properly if I ruled things out that, as we see from countries around the world, are being used selectively in appropriate circumstances to try to contain a virus.

“If I’m looking at the data and the evidence and I’m seeing that there’s a risk to Scotland of infection coming in from other parts of the UK and I think that there needs to be measures taken to contain that, then I will discuss that with other administrations as appropriate.”

Ms Sturgeon insisted her one objective during the pandemic is “trying to stop this virus getting out of control”.

She said: “That’s all that drives this decision-making process right now, and I really do say to people – whether it’s the leader of the Scottish Tories, the Secretary of State [for Scotland], or even the Prime Minister, who I have been at pains not to criticise over this – if you find yourself trying to turn any of this into a political or a constitutional argument, go and take a long hard look at yourself in a mirror.

“If you’re being honest with yourself, you will admit that you’re failing people or risking failing people, so I’m not going to do that.

“I’ve said from day one that however long this crisis lasts, I’m going to stick with it because I take my responsibility to the best of my ability to protect Scotland from this virus more seriously than perhaps I’ve taken anything in my life before.”

Scottish Secretary Alister Jack earlier described the idea of quarantining UK travellers as “divisive”.

He said: “What’s deeply regrettable is that the First Minister has encouraged reckless talk.

“It’s not the language which we should be hearing from our First Minister because it undermines the joint efforts that we’ve had in tackling Covid-19 and it’s bad for business and it’s especially bad for the tourism business.”