NICOLA Sturgeon has refused to rule out a hard border between Scotland and England after independence.

The First Minister told the BBC’s Andrew Marr show she did not want a border, but did not dismiss the idea of infrastructure and checks if Scotland was in the EU and England was out

She said: “It’s not my choice. But we have to take these things step by step.”

She added she would be "frank and honest with people in Scotland about the choices I’m asking them to make".

The opposition said the SNP's "mask has slipped" after years of the party refusing to acknowledge a hard border could be a result of different trading regimes in Scotland and England.

Ms Sturgeon was asked whether a hard border was avoidable if the UK underwent Brexit and diverged from EU rules and taxes, then Scotland went back in.

In that situation, the Scottish-English border would also be an EU external border, and so potentially subject to customs and regulatory checks.

Ms Sturgeon said English divergence from the EU regime after Brexit was “a real danger” and why she did not want Scotland to be “trapped” but to chart its own course.

She said: “I don’t underestimate the dangers and the damage of a Boris Johnson-led government in a race to the bottom prioritising trade deals with the likes of Donald Trump.”

Pressed on a potential hard border, she said: “I don’t want borders. It’s not my choice. But again, we have to take these things step by step.

“I am not the author of the Brexit policy. I am opposed to the Brexit policy. It’s not my choice to have policies that result in borders. I don’t want Scotland and I don’t see why Scotland does have to choose.”

When it was put to her she might nevertheless have to deal with a border being “foisted” on her, she said: “I will. But what I’m not going to do is to speculate and answer questions on the basis of detail that we don’t yet have, and a scenario that we don’t yet know the nature of. 

“So I will always be frank and honest with people in Scotland about the choices I’m asking them to make.

“One of the things I am determined about is that the choice that Scotland will make on independence, just as it was in 2014, will be an informed and a detailed one. We won’t plaster lies on the back of a bus and cross our fingers and hope we get away with it.”

Press again on whether a hard border was inevitable if Scotland was in the EU and England wasn’t, Ms Sturgeon said: “That question had a number of ifs in it, and that’s the point I am making. We need to see how things play out and what the final relationship between the UK and the EU will be. 

“I am not of the view that what you’ve described, what Boris Johnson wants, is an inevitability, and I will continue to argue against that. 

“But as that picture clarifies I will be honest with the people of Scotland. But that opens a situation where Scotland’s best interests depend on being independent and in charge of our own future, and I don’t want borders, it is not my policies putting borders anywhere.”

Asked how long she thought it would take Scotland to be admitted to the EU as an independent member state, Ms Sturgeon said: “Not very long. I’m not going to sit here and put a timescale on that because we would have to properly, responsibly, in a mature way, have these discussions.

“But I speak to people in the European institutions and member states regularly as part of my job as First Minister. I think there is a real appetite to see Scotland in the EU. 

“I think there would be open arms for Scotland. And I don’t think that would be a process that of necessity take a particularly long period of time.” 

Acting Scottish Tory leader Jackson Carlaw said: “Nicola Sturgeon’s acceptance that Scottish independence will most likely lead to a border with England is a dramatic shift.

“Up until now the Nationalists have refused to accept this as even a possibility but they are can see they are fooling no one.

“Sturgeon must now continue to be 'honest’ and admit that separation from the UK would lead to extreme austerity, hard borders with England and damage to public services.”

Scottish Liberal Democrat leader Willie Rennie said: “The mask has slipped. For Nicola Sturgeon any price is worth paying to break up the United Kingdom, even dividing friends and family with a hard border.

“The SNP should learn the lessons of Brexit, we need close ties with our neighbours not new barriers." 

Scottish Labour leader Richard Leonard added: "We need to resolve the constitutional crisis - not create another one."

Pamela Nash, chief executive of Scotland in Union, said: “Nicola Sturgeon’s refusal to rule out a hard border with England has exposed the devastating reality of leaving the UK.

“Creating a barrier with the rest of the UK following Scexit would cause unimaginable damage for our economy, as well as separating us from our families and friends.

“Sixty per cent of our trade is with the rest of the UK, demonstrating the importance of remaining in the UK for businesses and jobs.

“But Nicola Sturgeon is prepared to take a wrecking ball to our economy, take away the pound, and erect a hard border with England.

“The only way to avoid this catastrophic outcome is to remain in the UK.”