By David Wallace Lockhart
BBC News governmental correspondent
A clash betwixt the UK and Scottish governments could beryllium coming adjacent week.
The cause? The 2 governments are going successful antithetic directions connected the process for allowing idiosyncratic to alteration ineligible gender.
But look a spot deeper, and it's accelerated becoming a law quarrel.
When Holyrood passed authorities to alteration Scots to alteration their sex much easily, galore campaigners hoped it would gully a enactment nether a statement that's simmered distant successful Scottish authorities for years.
Currently, idiosyncratic looking to alteration their ineligible sex successful the UK indispensable unrecorded successful their acquired sex for 2 years and get a diagnosis of sex dysphoria.
MSPs backed a determination towards a self-identification strategy past month, meaning that Scots volition nary longer necessitate a aesculapian diagnosis to alteration gender, and the timescale volition besides beryllium chopped to a substance of months.
But, arsenic it turned out, that ballot successful Edinburgh was not the extremity of the issue.
The UK authorities is considering utilizing its ain powers to artifact the Scottish legislation, and ministers are uneasy astir the caller strategy that could soon run successful Scotland.
So what's their justification for perchance challenging laws coming from Holyrood?
They person concerns that a simplified Scottish strategy for changing sex could travel into struggle with UK-wide equalities instrumentality (something Holyrood is not liable for).
And this is prompting a fig of Conservative MPs to inquire questions astir what the implications could beryllium for the rights these radical would person successful immoderate different portion of the UK.
What does it mean for accessing definite spaces reserved for conscionable 1 sex, specified arsenic women's shelters oregon prisons? What's the interaction connected collecting and reporting information connected the sex wage gap?
The Scottish authorities insists that the measure does not undermine immoderate facet of the UK-wide Equality Act, saying that the caller strategy doesn't springiness immoderate further rights to anyone who gets a sex designation certificate that they can't already bask today.
Rishi Sunak told BBC Scotland connected Friday that his main interest was the bill's interaction crossed the UK, saying it was "completely modular practice" to look astatine the effect authorities passed astatine Holyrood could have.
Downing Street said nary last determination had been taken connected whether oregon not to artifact the legislation.
And the PM's spokesperson said they believed the UK's 2004 Recognition Act struck "the close balance" and allowed for "proper checks".
Conservative MP Rachel Maclean is simply a vice-chair of the party, and portion she whitethorn correspond a spot successful England, she's taken an involvement successful this Scottish legislation, arguing it could person tremendous impacts connected different parts of the UK.
She told the BBC: "We privation to beryllium compassionate to radical who consciousness that they privation to alteration their enactment and their ineligible gender, but astatine the aforesaid clip we person to marque definite that we support peculiarly single-sex spaces for women.
"They are determination for a crushed - to support those susceptible women and girls."
She's sceptical astir the streamlining of the process successful Scotland, saying it is efficaciously allowing self-identification - which creates "a immense fig of consequences".
She says she worries astir knock-on effects erstwhile it comes to information successful sport, the arts, and business.
She adds: "That's earlier we truly commencement talking astir wherever we person vulnerabilities astatine play, specified arsenic successful prisons oregon successful rape and home maltreatment shelters."
She argues it has "enormous impacts crossed the full of our extortion model and our knowing of what does it mean to beryllium a antheral oregon a woman".
This is an contented that divides a fig of parties. Even wrong the SNP, the Scottish authorities has its critics.
Though the SNP-led authorities successful Scotland spearheaded the bill, it sparked the biggest rebellion the enactment had ever seen astatine Holyrood.
Ash Regan resigned arsenic a Scottish authorities curate successful bid to reason the legislation, and said the measure "sent a connection to the women and girls of Scotland that your rights to privacy, dignity and information don't matter."
But supporters of the measure spot it differently. Campaigner Ellie Gomersall, who is president of the National Union of Students successful Scotland, and a Scottish Green Party activist, has been a vocal advocator for a alteration to sex laws successful Scotland.
She came retired arsenic trans erstwhile she was 18, and is hoping to legally alteration her sex and get a Gender Recognition Certificate (a GRC).
Ellie says it was "such a relief" erstwhile the measure was passed successful Scotland.
"One of the hardest parts astir being trans is the admin," she explains, saying that she's faced a five-year hold to entree an NHS sex individuality clinic.
She says the trans assemblage volition combat immoderate UK authorities attempts to obstruct the caller Scottish system.
She sees their effect arsenic "an onslaught yet connected devolution, connected trans people, and connected Scotland's close to marque our state fairer and much equal".
Kade lives successful England and, arsenic a transgender man, believes UK authorities policies lend to a hard ambiance for trans people.
"Nobody is going to beryllium transgender for fun," helium says, adding that helium was hospitalised aft a transphobic onslaught 2 years ago.
"We don't consciousness safe, we don't consciousness valid, and we're acrophobic I think. Although we effort not to fto this fearfulness interaction america connected a regular basis, determination is that underlying fearfulness for some our intelligence wellbeing and our carnal wellbeing."
Rather than artifact the Scottish legislation, helium wishes the UK authorities would emulate it.
If the UK authorities does privation to act, it doesn't person a batch of time. The Scotland Act stipulates a four-week clip bounds to intervene aft MSPs walk a bill. That gives them until the mediate of adjacent week.
So what are the UK government's options?
Under Section 35 of the Scotland Act, UK ministers tin halt a measure getting royal assent.
The caput of authorities for Scotland tin bash truthful if they deliberation a Holyrood measure would modify laws reserved to Westminster and person an "adverse effect" connected however those laws apply.
This would beryllium the atomic enactment - a conception 35 bid has ne'er been used. And it's wholly imaginable determination could beryllium a ineligible situation successful effect from the Scottish government.
One Scottish authorities root said utilizing a Section 35 Order would beryllium "chilling". Scottish ministers would spot this arsenic the UK authorities muscling successful connected a devolved area.
The UK authorities has besides not ruled retired the anticipation of referring the Scottish measure to the Supreme Court, who could determine if Holyrood legislated beyond its powers successful passing this act.
This full statement is - connected the aboveground - astir sex issues.
But similar truthful galore disagreements betwixt governments successful London and Edinburgh it has the constitution astatine its heart.