Nicola Sturgeon has insisted her government is “looking at all options” available to challenge Alister Jack’s use of a section 35 order to block Scotland’s gender recognition reforms.

The First Minister said it was important that a “judicial interpretation” of a section 35 order was sought to ensure the UK Government cannot use its “blank piece of paper power” to halt legislation passed by Holyrood “any time they have a political disagreement”.

Ms Sturgeon, speaking at a press briefing, said that Scotland’s minimum unit pricing for alcohol could have been targeted by UK ministers if the use of a section 35 had taken place in the first instance, at an earlier date.

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The gender recognition reforms, overwhelming backed by MSPs, would remove the need for trans people to require a gender dysphoria diagnosis to obtain a gender recognition certificate, with a move to a system of self-ID.

The plans would also reduce the lower age limit form 18 to 16.

But the UK Government has used a section 35 order for the first time in the history of devolution to block the legislation and prevent it from becoming law.

Mr Jack, the Scottish Secretary, has moved to justify the move by insisting that the legislation would have an impact on UK-wide laws such as the Equalities Act.

He also raised concerns about two parallel gender recognition systems operating despite the matter being devolved to Holyrood.

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It is likely the Scottish Government will need to challenge the use of the section 35 through the courts, but the FM said she was “looking at all options” of how it could be challenged, stressing that “the use of a section 35 order is unprecedented”.

She added: “There’s no precedent to look at in terms of how to challenge that.”

The FM said that there “might be no other option” than to seek a judicial review in the courts but added that the Scottish Government is “looking to see whether” an alternative challenge “is possible”.

Ms Sturgeon said that there are two fundamental reasons why the decision should be challenged – firstly pointing to an ability to allow the legislation to become law.

But she warned there was a “real public interest” in obtaining “some judicial interpretation” on when a section 35 order can be used”.

The First Minister suggested that clarity is needed in law so that it cannot “be used pretty much on the whim” of UK ministers “any time they have a political disagreement” with Holyrood.

Read more: Alister Jack snubs Holyrood committee over gender reforms block

She added that the UK Government has a “blank sheet of paper power” through a section 35 order which allows Tory ministers to “overturn the decisions in areas of devolved competence” they do not agree with or support.

Asked what other forthcoming pieces of legislation could be subject to a section 35 order, Ms Sturgeon said it would “be very difficult” to know “with any confidence, which bills were safe from that”, because the use could be “so unfettered”.

Ms Sturgeon also condemned some placards displayed at a rally protesting against the UK Government’s veto of Scottish legislation to reform the gender recognition process.

SNP MP Kirsten Oswald and her party colleague, MSP Kaukab Stewart, were pictured with the signs in the background calling to “decapitate terfs” – referring to trans exclusionary radical feminists – provoking criticism from Harry Potter author JK Rowling among others.

Questioned on the signs, Ms Sturgeon said she had attended demonstrations where placards were displayed that did not align with her views.

She said: “Certainly, from the images I have seen, I think that was the case at the demonstration on trans rights on Saturday.

“The placards that I have seen in no way – absolutely no way shape or form – accord with my views and I would condemn the way in which those views were expressed and the views that were expressed there.

“And I don’t think it’s fair or credible to suggest that the elected representatives that were there in any way share or condone those views.”