NICOLA Sturgeon will face a further SNP rebellion next month when legislation making it easier for transgender people to change their legal sex comes before the Holyrood for the final time.

The SNP suffered its largest backbench revolt last month in its 15 years in power over the Gender Recognition Reform Bill with one minister resigning in order to vote against the plans.

Ash Regan, the community safety minister, quit, prompting the First Minister to accuse her of failing to raise her concerns with colleagues. Seven SNP members voted against the party whip and two abstained.

However, the bill was voted through stage one to applause across the Holyrood chamber, following an intense and at times emotional debate.

The plans, backed by all the parties in Holyrood apart from the Conservatives, introduce a system of self-declaration for obtaining a gender recognition certificate (GRC).

The bill removes the need for a psychiatric diagnosis of gender dysphoria, reducing the time someone must have been permanently living in their acquired gender before they can apply, from two years to three months, and dropping the age at which people can apply from 18 to 16, in line with wider Scots law on legal capacity.

But some opponents of the reforms are concerned about their possible impact on the rights of women to have single sex spaces and services under equality legislation.

The legislation is now due to be further scrutinised by Holyrood’s Equalities, Human Rights and Civil Justice Committee at stage two of the parliamentary process.

The second stage is expected to take place over two committee hearings later this month, and any MSP can suggest changes but only members of the committee can vote on whether they are adopted. An SNP revolt is not expected at the second stage.

The whole parliament can then propose and vote on amendments in the third and final reading of the legislation, due to take place before the end of the year. It is at this final stage that a further SNP rebellion is expected.

Christine Grahame, the SNP MSP, is due to put down an amendment at stage two which she believes would provide more safeguards to people aged 16 to 18.

Labour is due to table changes calling for the legislation to explicitly call for guidance on the interaction between the proposals and the Equality Act.

However, SNP MSPs rebels who have spoken to The Herald on Sunday, have indicated they are not likely to change their minds even when the bill is amended and believe the issue should not have been subjected to the party whip.

The Scottish Conservatives allowed a free vote on the matter, and while the party’s position was opposed to the bill, two of its MSPs voted in favour while a further two abstained.

A free vote was denied by the SNP at stage one because of the leadership’s pact that brought the Scottish Greens into government. Reform of the gender recognition act was a red line for the Scottish Greens in their cooperation agreement with the SNP following the Holyrood elections in May last year.

Some of the SNP critics say they are fundamentally opposed to the principle of gender self-identification and revising the details won’t persuade them to change their minds.

One who voted against the bill was asked whether a possible amendment on increasing the age to 18 or providing more assurances that women’s rights to single spaces and services, would persuade them to back the bill.

“Absolutely not as my fundamental issue is with self-ID and I have no expectation whatsoever that that will be rolled back from. So for me no,” said the MSP.

The rebel was asked if the fundamental objection was also the position of colleagues who did not vote with the government last month.

“I consider it highly likely that the others, though I’ve not spoken to them, that that would continue to be likely.

“In other words when you are operating on the basis of a principled objection, it’s not going to shift by a little bit of tinkering,” said the MSP.

“What I would need [to support the bill] would be a removal of self-ID and [the introduction] of gate keeping.

“How you do that would be up for discussion. For instance it could be a doctor’s diagnosis of gender dysphoria. The principle of self ID carries risks and I think we have to acknowledge that in terms of mitigation of those risks.”

A second SNP MSP who did not support the government also made clear they were not minded to change their position when the bill came to a final vote.

“I would love to be able to vote for legislation that improved the lives of this vulnerable minority but the bill as it stands is seriously flawed,” said the critic.

“The amendments that have been mooted slightly improve things, however, I have a way to go to be convinced that they address my key concern that is how single sex spaces are maintained for the purposes of dignity, privacy and in therapeutic settings.

“No sanction or reward could make me vote for something that I believed would put women and girls in harm’s way. I know many of the public have been dismayed that MSPs were not given a free vote on this matter.

“Most simply don’t understand how something that is clearly divisive and speaks to members deeply held beliefs and values was so rigidly enforced by whips and special advisors and not left to the conscious of their elected representatives.”

John Mason, SNP MSP who voted against the bill, is also unlikely to change his mind ahead of the final vote.

During last month’s Holyrood debate Mr Mason underlined his fundamental opposition to the legislation arguing that the sex a person is born as cannot be changed.

“There are certain things that we need to accept as scientific or medical facts. The earth goes round the sun once a year, and days are shorter in winter. Those are facts, whether we like them or not, and we have to accept them,” he said.

“I understand it to be a fact that there are two sexes: male and female. Each person is born on a certain day, in a certain place and with a certain mother, all of which is recorded on a birth certificate. A person’s biological sex is discovered on that day, or possibly earlier if scans are used, and that biological sex cannot be changed. That is important, especially for healthcare rights later in life.”

Mr Mason was asked by The Herald on Sunday how he would be voting in December.

“You saw what I said in my speech. These are fundamental things like blurring the line between who is male and who is female,” he said.

“So I would be surprised if amendments could deal with that.”

However, he added he wouldn’t make a final decision until the day of the vote.

On the other side of the debate, the Scottish Greens’ Maggie Chapman, one of MSPs who has advocated support of moving to the system of gender self-identification, has concerns that the proposed periods of living in an acquired gender are too long.

In her speech, she objected to a measure in the bill to prosecute someone who may start the process of self-identification but later change their mind. She also wants to see a faster process for the terminally ill.

“We are not yet where we want to be. The bill itself does not do everything that we want it to do. Some of those gaps can potentially be filled in the stages ahead of us,” she told Holyrood in the debate.

“I make no secret of—and no apology for—my call for the three-month waiting period and the three-month reflection period to be taken out of the bill, for a reconsideration of the problematic person of interest provisions, for the removal of the redundant and stigmatising new criminal offence and for proper end-of-life provisions to be secured.”

It was voted through at stage one by 88 votes for to 33 against, with four abstentions, including seven SNP members voting against the party whip and two abstaining.

The rebellion reflected a heated public discourse around the bill.

Supporters say transgender people have acutely suffered due to the medical process and two year period of having to live in their acquired gender to obtain a certificate as stipulated under the UK’s Gender Recognition Act 2004.

Opponents, however, argue it will fundamentally alter who can access women-only services and believe they have not been adequately consulted.

Last month the Scottish Greens voted to suspend ties with the Green Party in England and Wales over the issue of trans rights.

Party members in Scotland accused their sister party for not making a sufficient commitment to tackle phobia against transgender people.

During that debate Scottish Greens members asked why they should suspend ties with the GPEW when some of their members were opposed to gender self identification, while maintaining formal links with the SNP through the Bute House agreement while some members of the larger party were opposed to gender self-identification.

Guy Ingerson, who proposed the motion, explained why he thought the party should continue to support the deal with the SNP.

“With the SNP, we are getting something in return. I don’t mean that in a cynical, transactional way. I mean it in a very positive way,” he said.

“We are getting a full ban on conversion therapy. We are getting improvements to trans health care and we are also getting GRA reform passed as well.

“So even though they do have a very serious issue with this, we are actually managing to implement though the co-operation agreement policies that will help the trans community in particular and all members of the LGBT community in a very positive way. That’s the clearest difference I can think of.”

A Scottish Government spokesman said: “There is overwhelming support for the Bill, with over two thirds of the Parliament and members of all five parties voting in favour at Stage 1.”

No disciplinary action has been taken against the SNP rebels to date.