Scottish Labour has pledged to “bring people together” over the issue of gender recognition reform after an intense Holyrood debate on proposals to make it easier for transgender people to change their legal sex that saw the Scottish National party suffer its biggest backbench revolt in 15 years of government. Although the gender recognition reform bill easily passed the first of three legislative stages on Thursday evening with a vote of 88 MSPs in favour to 33 against, with four abstentions, as the legislation enters the amendment stage supporters are concerned that some key elements – such as the reduction in the age someone can apply for a gender recognition certificate to 16 – may be lost. And during the debate speakers warned that – although reform is now supported by every party in Holyrood bar the Scottish Conservatives – the Scottish government cannot expect cross-party support to continue if it does not address significant concerns that have been raised. The community safety minister, Ash Regan, resigned just before Thursday’s debate in order to oppose the government, later releasing a statement that explained: “I am not against reform per se, however, I cannot support any legislation that may have negative implications for the safety and dignity of women and girls.” Scottish Labour’s social justice spokesperson, Pam Duncan-Glancy, said on Friday that Labour would seek to amend the bill to make clear that nothing in it affects the protections in the Equality Act – a central concern of critics of the proposed legislation – in order to “bring people together, reassure those with concerns, and deliver legislation that everyone can have confidence in”. The gender recognition reform bill proposes a system of self-declaration for obtaining a gender recognition certificate (GRC), removing the need for a psychiatric diagnosis of gender dysphoria, reducing the time someone must have been permanently living in their 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. Glancy said: “Labour are the party of equality and human rights. We are determined to make sure the GRA is reformed and de-medicalised, and that this bill strengthens and protects the rights of all.” During Thursday’s debate, the social justice secretary, Shona Robison, assured MSPs that she would have an “open-door policy” to those wanting to bring concerns or discuss potential amendments. Any MSP, as well as the Scottish government itself, can raise an amendment to the bill at the second stage – when the committee will go through the draft line by line – provided it is within the scope of the legislation, before it returns to the chamber for further debate and votes at stage three. The Guardian understands that the EHRC – which has been consistently critical of the proposals after changing its position on reform at the start of the year – raised the possibility of suggesting areas for amendment with Robison at a recent meeting, which she said she was happy to discuss. It is also understood that the Scottish Conservatives, who allowed their MSPs a free vote which saw two members breaking ranks to support the bill yesterday, plan to put forward an amendment retaining the minimum application age at 18. After the intensity of Thursday’s debate, there was some optimism on Friday from MSPs on both sides of the issue: from those who point out that the key principles of reform received emphatic cross-party support, and those who believe that the highly unusual SNP revolt could inspire further collaboration at the next stage. Some SNP MSPs expressed frustration that a promised group discussion on whether to allow a free vote on the bill did not take place earlier this week. On Friday party officials refused to comment on what consequences those members who broke the whip would face, saying it was an internal matter. SNP supporters of the bill are worried that the number of rebels means that, even with Green support, the government may lose some amendments if it loses cross-party support. Scottish Trans welcomed the broad support for the bill from MSPs, but added that “in the chamber it was unfortunate to hear some of the same misinformation we’ve been challenging for years alongside some misgendering and misunderstandings of what it means to be trans.” The interaction between the bill and the Equality Act will be further challenged at next month’s hearing of a long-running court case brought by the campaign group For Women Scotland, which opposes self-declaration, against the Scottish government in relation to the Gender Representation on Public Boards (Scotland) Act 2018. The Scottish government is expected to argue that a GRC changes someone’s legal sex under the 2010 Act, which critics believe conflates the protected characteristics of sex and gender reassignment and effectively would end single-sex provision.