It is the great new divide in British politics. No longer are the parties defined by their attitudes to taxation and spending. Gone are the days when great ideological arguments were joined over the limits of state interventionism. Worryingly, there is a growing pre-Thatcherite consensus emerging around these issues, a return to what was dubbed Butskellism in the late 1950s.

No, the great schism today is gender based, or, more accurately, biological.

In the Commons last week, Boris Johnson made his position clear. “We must recognise that when people want to make a transition in their lives that they should be treated with the maximum possible generosity and respect [but] when it comes to distinguishing between man and woman, the basic facts of biology remain overwhelmingly important.”

Who could possibly disagree with that statement or find it remotely contentious? Obviously, a vanishingly small group of activists fulminated that this was somehow intolerant of people seeking to assert their gender identity through surgery, which it clearly wasn’t. But I suspect the vast majority of people are with the Prime Minister on this and would not consider what he said to be controversial or lacking in compassion.

Moreover, at least he was prepared to say it, unlike Sir Keir Starmer. Asked on LBC radio whether a woman can have a penis, the Labour leader got into a right old fluster. “I don’t think we can conduct this debate … in this way,” he told interviewer Nick Ferrari. “I don’t think discussing this issue in this way helps anyone. I want to have a discussion [with]… anyone who genuinely wants to find a way through this.”

What on earth is he talking about? To find a way through what, exactly – how to say something that is true without being denounced by a handful of very vocal campaigners? Labour spokesmen have evidently decided to run away whenever they are asked a question that just a few years ago would not even have occurred to anyone.

When Yvette Cooper, the shadow home secretary, was asked recently to define what a woman is, she said she didn’t want to go down that “rabbit hole”. Anneliese Dodds, who speaks for Labour on women’s issues, got into an even bigger tangle when the same question was put to her. “It does depend on the context surely. There are people who have decided that they have to make that transition… because they live as a woman they want to be defined as a woman.”

Her comments prompted the author JK Rowling to suggest Ms Dodds might be in need of both a dictionary and a backbone. And therein lies the point. This is no longer a debate about gender but free speech.

Rowling, the country’s most successful living writer, has been excoriated for seeking to defend the rights of women from the trans lobby’s encroachment on their hard-won advances over the decades. She is a big enough international figure to withstand the brickbats. According to her publishers Bloomsbury, the sales of her Harry Potter books remain unaffected by the stand she has taken.

The same cannot be said for Graham Linehan. Few people have made me laugh as much over the years as Linehan, whose Father Ted and The IT Crowd are masterpieces of the surreal comedy genre. Yet because he has fallen foul of trans activists by standing up for women’s rights, his entire career has been trashed. He broke down during a TV interview at the weekend as he described how he had lost his commissions and his marriage had collapsed. A stage musical version of Father Ted has been axed just as it was in rehearsals, while media companies and showbusiness friends have turned their backs on him. “They took everything from me,” he said.

But who are “they”? At least with the Inquisition you knew who was behind it and what the consequences were for challenging theological orthodoxy decreed by the medieval Church. But who are today’s Torquemadas metaphorically dragging heretics to the stake?

This is being perpetrated by pusillanimous politicians, craven corporate bosses and spineless luvvies who lack the guts to stand up to the new fanaticism, even if it means trampling on the rights of those who are prepared to confront it. They fear that they will be targeted and yet it is in their hands to end the madness by not “cancelling” those deemed by a tiny minority to have uttered something they don’t like.

Unless politicians like Sir Keir call this nonsense out, the lunatic fringe will prevail and the voters will take note of who stood where, not least women who see their rights being so carelessly set aside.

The Labour leader has claimed that the law states that trans women are women, drawing a withering response from Rowling who said it was “yet another indication that the Labour Party can no longer be counted on to defend women’s rights”.

They cannot be counted on either to defend the right to free speech by supporting those, even in their own party, who disagree with what is an eminently contestable point of view. Angela Rayner, the party’s deputy leader, sank deeper into the mire yesterday by saying it was reasonable “in some circumstances” to ask a trans man if they were pregnant. She added: “It wouldn’t be a reasonable question for me to say ‘Have you got a penis or not?’ because that’s not acceptable.” But no one is suggesting that. It is an Aunt Sally to duck the real issue. No sensible person wants to see trans people ostracised.

Labour suffered at the polls in 2019 because it was led by someone who voters thought totally unsuitable to be prime minister. Traditional Labour seats fell like ninepins not necessarily because they had warmed to Boris but because Jeremy Corbyn was considered weak and unpatriotic.

Sir Keir and his front-bench team are alienating voters once again with their absurd refusal to say what everyone knows to be true on the spurious grounds that it would be intolerant to do so. Yet the bigotry is coming from radical trans activists, not the other way round, by shutting down the very discussion that Sir Keir said he is so anxious to have but clearly isn’t.

A politician who refuses to say whether a woman has a penis or a man a cervix is not fit to lead a government. If he carries on doing so he never will.