Labour's split over gender rights deepened today as a former justice minister described Rishi Sunak veto of a Scottish law as 'a nuclear weapon used in a minor skirmish'.
Lord Falconer, who was Lord Chancellor under Tony Blair, said the Prime Minister's use of devolved powers to stop Holyrood's Gender Recognition Reform Act from receiving Royal Assent was not justified.
But his comments online last night came after a day where deep splits in the party over the rights of transgender Brits were exposed.
Canterbury MP Rosie Duffield was jeered in the Commons by Labour MPs as well as the SNP as she backed the Government's decision to block the Scottish parliament's legislation.
Meanwhile party leader Sir Keir Starmer has yet to publicly reveal where he stands on the legal move. On Sunday he said he disagreed with parts of the Scottish law involving lowering the age at which people can legally change gender to 16.
The Government's decision to use Section 35 of the Scotland Act to prevent the Bill from gaining royal assent is the first time such powers have been used since Holyrood was established in 1999.
In a series of tweets last night Lord Falconer outlined his opposition to the move. Whether the s35 Order is justified depends on reasons advanced by (the government) for saying (the new law) has adverse effect on UK equality law,' he said.
'For the reasons I have tweeted those reasons do not begin to justify its use. It's a nuclear weapon used in a minor skirmish.'
Lord Falconer, who was Lord Chancellor under Tony Blair, said the Prime Minister's use of devolved powers to stop Holyrood's Gender Recognition Reform Act from receiving Royal Assent was not justified.
Party leader Sir Keir Starmer has yet to publicly reveal where he stands on the legal move. On Sunday he said he disagreed with parts of the Scottish law involving lowering the age at which people can legally change gender to 16.
Scotland's First Minister, Nicola Sturgeon, has already branded the move a 'full-frontal attack on our democratically-elected Scottish Parliament and its ability to make its own decisions on devolved matters'.
She told the BBC the decision will 'inevitably end up in court'. In Westminster, the UK Government was understood to be braced for drawn-out legal wrangling.
Ms Duffield was attacked after asking the Scottish secretary Alister Jack to 'recognise the strength of feeling amongst women, women's rights' groups and activists in Scotland, that this Bill seeks to allow anyone at all to legally self-identify as either sex and therefore enter all spaces, including those necessarily segregated by sex, such as domestic violence settings, changing rooms and prisons'.
She had to raise her voice as she was heckled by Labour and SNP MPs who support the Scottish plan.
Former Labour cabinet minister Ben Bradshaw shouted 'absolute rubbish' as she spoke, while fellow Labour MP Lloyd Russell-Moyle also appeared to be trying to shout her down.
Canterbury MP Rosie Duffield was jeered in the Commons as she backed the Government's decision to block the Scottish parliament's gender identification legislation
Shadow armed forces minister Luke Pollard and former frontbencher Charlotte Nichols could also be seen shaking their heads in dissent.
Mr Jack said Ms Duffield 'deserves a lot of respect for her courage on standing up on this issue'. Writing later on Twitter, Ms Duffield said: 'Being shouted down in the Chamber by Labour men who clearly don't want women to speak up for our rights to single-sex spaces. How very progressive.'
She added: 'The protection of single sex spaces for the most vulnerable women are at stake, so why on earth are Labour colleagues OK with this?'
The Labour leadership was unwilling to say whether it backed the Government stance.
Shadow Scottish secretary Ian Murray dodged the issue and accused ministers of turning the row into a political 'bun fight'.
The prominent Labour MP asked the Scottish secretary Alister Jack to 'recognise the strength of feeling amongst women, women's rights' groups and activists in Scotland'
Shadow culture secretary Lucy Powell flatly refused to reveal her views on the issue. She told Times Radio there were 'a range of different opinions across Labour', adding: 'I have my own views, which I'm going to keep to myself... I'm not going to answer because I don't want to reduce this argument to that.'
Scotland's First Minister Nicola Sturgeon was yesterday accused of 'weaponising vulnerable children', as she vowed to take the Government to court for blocking gender self-identification.
Amid angry scenes in the Commons, Tory MPs claimed the SNP was stoking the row about trans rights in a cynical 'pursuit of their separatist agenda'.
Scottish Secretary Alister Jack told MPs the decision to block the bill followed legal advice it would have 'serious adverse effects' on provisions in the Equality Act
The accusation came as the SNP leader vowed to fight the Government all the way to the Supreme Court over its 'outrageous' decision to veto a Scottish parliament law, the Gender Recognition Reform (Scotland) Bill, that paved the way for gender self-identification. She said the row would 'inevitably end up in court'.
Ms Sturgeon accused the Government of mounting 'a direct attack on... Scottish parliament', adding: 'If it is allowed to happen on this, then I think that is a very slippery slope.'
The Scottish secretary told MPs the decision to block the bill followed legal advice it would have 'serious adverse effects' on provisions in the Equality Act that guarantee women's access to single-sex spaces.