Scotland’s Social Justice Secretary has condemned the “increasing draconian” UK Government after it confirmed legislation to reform the gender recognition process north of the border will be blocked.

Scottish Secretary Alister Jack has announced he will make a Section 35 order – a never before utilised section of the 1998 Scotland Act – to prevent the Gender Recognition Reform (Scotland) Bill from gaining royal assent.

Scottish First Minister Nicola Sturgeon has branded the move a “full-frontal attack on our democratically-elected Scottish Parliament and its ability to make its own decisions on devolved matters”.

But Mr Jack claimed the reforms – which simplify the process for trans people to obtain a gender recognition certificate (GRC) – could have “chilling effects on single-sex spaces” for women.

He also warned of “significant complications” from having different processes for obtaining a GRC in different parts of the UK.

Shona Robison, the Social Justice Secretary at Holyrood, insisted that Scottish ministers are “very, very confident in our position of this legislation being competent”.

Mr Jack, who will make a statement in the House of Commons on Tuesday, has claimed the Bill as passed would have an “adverse impact on the operation of Great Britain-wide equalities legislation”.

Downing Street suggested it was “forced” to block the law in order to uphold the Scotland Act.

The Prime Minister’s official spokesman said: “It’s with regret that we’ve been forced to take this unprecedented approach. It’s significant that this is the first time we’ve ever had to consider using Section 35.

“And of course, it’s important to understand that if we did not take this action, we would not be upholding the Scotland Act, which set out that Scottish Parliament should not legislate in areas where there may be adverse effects on GB-wide legislation and of course equalities is part of that.”

The UK Government would not accept any revised Bill that would have “such a significant impact” on equalities matters across Great Britain, the spokesman added.

Ms Robinson told BBC Radio Scotland’s Good Morning Scotland programme: “We’re very confident it does not impact on UK legislation, and we will take whatever steps we need to ensure the democratic will of the Scottish Parliament is not frustrated.”

The Bill was passed by an “overwhelming majority” at Holyrood last month, with MSPs from all political parties backing it, she said.

Ms Robison continued: “We are very confident in our legislation, this is legislation that is completely devolved, it is within the competence of the Scottish Parliament.”

She argued that blocking the Bill from gaining royal assent is “the action of an increasing draconian UK Tory Government”, saying: “It is not just this they have done, this is the latest in a string of actions undermining rights, from laws to ban strikes to other areas of people’s rights, to now using one of the most marginalised groups as a political weapon.”

She accused Mr Jack of “wanting to throw his weight about”, and claimed there are also some members of Rishi Sunak’s Government who “want to row back on human rights and equalities legislation”.

But she declared: “We will not stand for it.”

Mr Jack has urged the Scottish Government to bring back an amended Bill for consideration, but Ms Robison said: “If Alister Jack wants to come forward with suggestions that do not undermine the principle of the Bill, that is fine.

“But I suspect this is about stopping a Bill they do not like, it is not about compromising around the margins of it.”

The legislation allows, for the first time, transgender people in Scotland to obtain legal recognition in their preferred gender without the need for a medical diagnosis.

It would also cut the time they have to live in their acquired gender before applying for a GRC, and reduce the age at which an application can be made to 16.

Ms Robison insisted: “It doesn’t impact on UK equality law, it simplifies the process for obtaining a gender recognition certificate. It doesn’t affect the purpose or the use of that gender recognition certificate.

“The Bill itself had an amendment that put beyond doubt that this had no impact on the Equality Act of 2010, and the UK Government itself had multiple opportunities to comment during the very extensive consultation on the Bill and its passage and they did not do so.

“Let’s be very clear here. If the UK Government thought there was a legal basis to challenge the Gender Recognition Bill, they would have done so in the Supreme Court through a Section 33 Order, as they have done previously.

“Using what is this nuclear option, the Section 35, never used before, I think does reveal there is no legal basis to challenge it.

“This is all about politics, and I think using one of the most marginalised groups in society as a political weapon is simply outrageous.”

Scottish Conservative equalities spokeswoman Rachael Hamilton accused Ms Sturgeon’s Government of having refused to listen to those who raised concerns about the Bill’s impact on single-sex spaces.

She told BBC Radio Scotland: “Legal experts have given advice to the Secretary of State for Scotland and they have said the Bill will have an effect on the operation across the United Kingdom, they have said it will affect the operation of the Equality Act, namely in single-sex spaces.

“The Scottish Government were warned about the cross-border issues and the effect it would have on single-sex spaces but they didn’t listen to the voices of women’s organisations who raised those concerns.”