In the first hustings event of the campaign to replace Nicola Sturgeon, leadership rivals Humza Yousaf, Kate Forbes and Ash Regan set out their differing positions on the issue.
Whether or not to launch a judicial review of the UK Government’s unprecedented use of a Section 35 order will be one of the most pressing items in the next First Minister’s in-tray.
The use of the veto means that the Gender Recognition Reform Bill, which would have made it far easier for people to change gender and from a younger age, has been left in limbo.
Mr Yousaf received the warmest response from the audience of SNP members in Cumbernauld Theatre when he said he was “unequivocal” that the veto should be challenged.
“Let me make sure that you are hearing me: we must challenge Section 35. We absolutely have to,” he said to loud applause.
“This is about the principle of our democracy. If we cave in, if we roll over to a Westminster power grab, they will come after legislation after legislation after legislation.
“What kind of message does that send to the Scottish people, that we’re not willing to stand up for devolution?”
Ms Forbes said she would “seek legal advice” on the issue, but that she would be reluctant to launch a judicial review as she believed the legislation could be amended at Holyrood.
Ms Regan, who resigned as a Scottish Government minister in protest at the GRR Bill, said the SNP had “lost the trust of the country” on the issue.
“I wouldn’t challenge the Section 35, not because I think that it’s OK for the UK to challenge our legislation, but for the simple reason that we’re going to lose that court case,” she said.
“We are going to be throwing probably hundreds of thousands of pounds of public money into something that the public don’t support.”
Elsewhere, Ms Forbes outlined what she would do to advance the cause of Scottish independence, saying she would seek the transfer of the legal powers for Holyrood to hold a second referendum from Westminster within three months of the SNP winning the next general election.
Mr Yousaf, meanwhile, said the case for independence should be broken down into “bite-size chunks” for activists to deliver on doorsteps rather than producing a “giant prospectus”.
The hustings was chaired by SNP president Michael Russell, who reminded the audience of party members that this was a “contest among friends” and that they should be respectful.
A further eight events have been scheduled in venues across Scotland over the next fortnight, with the next taking place on Friday evening in Glenrothes.
Two more live televised debates featuring the three contenders for the SNP leadership have been confirmed by the BBC and Channel 4.
Channel 4 will air a 30-minute debate on 9 March at 7pm, hosted by Krishnan Guru-Murthy. Scotland’s Next Leader will involve the candidates debating set topics and challenging each other.
The BBC said that they had also agreed to take part in a special edition of its Debate Night programme on BBC1 at 8pm on 14 March. They will field questions from host Stephen Jardine and a studio audience in an hour-long show.
The first live TV debate is due to be shown by STV at 9pm on 7 March.