HOLYROOD’S Presiding Officer has refused to second guess the legality of a Referendum Bill that lacks consent from Westminster.

Former Green Alison Johnstone said she would only “react to any Bill as and when it arises”.

Such a Bill could prove one of the biggest controversies of the new parliamentary term.

Nicola Sturgeon insists there is a mandate for a second referendum in the current term, given the SNP’s 64 seats in last month’s election.

Although the SNP fell one short of a majoriyty, the trigger for the 2014 vote, together the SNP and pro-independence Greens do have a majority, with 71 of 129 MSPs.

However Boris Johnson has so far refused to give Holyrood the power needed to hold a legally wateright Indyref, saying “now is not the time”, given the focus on recovery from the pandemic and the relatively recent No vote.

The First Minister - who wants Indyref2 by 2024, Covid permitting - has said that if the PM continues to block it, she will put a Referendum Bill through Holyrood regardless, effectively daring the UK Government’s law officers to challenge it at the Supreme Court.

It would be for the Scottish Government’s chief law officer, the Lord Advocate, to make the critical decision on whether such a Bill was within Holyrood’s competence.

If they did, Ms Johnstone would then say if she agreed, although her opinion would only be advisory, and MSPs could debate and pass the Bill even if she said it was ultra vires.

Asked by the PA news agency about the possible competence of such a Bill, Ms Johnstone told the PA news agency: “I will deal with that as and when it arises.

“At the point in time of any Bill coming before me with a question of legislative competence, I am well briefed by expert advisers.”

She said she wanted to ensure debates on the issue were “respectful and courteous”, despite the strong feelings involved.

She said: “We’re leading the debate in Scotland, so I think it is important we set a good example and show you can robustly disagree with one another but you can do that in a courteous manner.”

The Lothians MSP also wants the remote working started at Holyrood to cope with the pandemic to carry on after it, to make the parliament more family friendly.

She said she was “very much a fan” of the hybrid model, in which some MSPs take part in debates, committees and votes in person, while others partictipate online.

It would be a “regressive step” for Holyrood to end those flexible ways of working, she said.

SNP MSPs Aileen Campbell and Gail Ross and Labour’s Jenny Marra all stepped down in May, citing the struggle to balance family life with a career in politics.

Ms Johnstone said: “I’ve heard very, very few people say ‘I wish I could go back to how it was before’.

“Obviously we all want to get back to normality, we want to be able to visit our friends indoors, we want to be able to socialise as we did before, but the thing we don’t want to go back to that insistence that work is somewhere that you go, rather than something that you do.

“We can get the balance right.”