Within a few years the Tory Party will almost certainly have adopted all-women shortlists to select parliamentary candidates. Opinion is changing at great speed on this issue, at least among those Tories who have given any thought to it.

Ed Miliband’s jibes at Prime Minister’s Questions last Wednesday have had the useful effect of drawing attention to the question. The Labour leader waved at the row of ministers facing him and said:

“A picture tells a thousand words. Look at the all-male front bench ranged before us.”

My first thought was that in Miliband’s case, a picture tells two thousand words (a joke borrowed from Tom Stoppard’s play Night and Day). The second thought was that Miliband was being un-prime-ministerial, a view confirmed when he went on to say:

“I guess they did not let women in to the Bullingdon Club either, so there we go.”

Miliband uses the Tories’ shortage of women to make cheap cracks: a displacement activity which helps him avoid talking about the economy, a subject on which he has nothing to say. But my third thought was that for reasons which have nothing to do with the Labour leader, it would be a good thing to go on increasing the number of Conservative women MPs.

No one knows more about this subject than Anne Jenkin (now Lady Jenkin of Kennington). In 2005 she launched the Women2Win campaign with Theresa May, in order to get more women into Parliament, and she still chairs it. This has made an enormous contribution to the rapid increase in the number of Conservative women MPs, from 17 at the 2005 general election to 49 in 2010.

But when Louise Mensch left Westminster for New York, that number fell to 48, and there is now a sense that the campaign has lost momentum, and that Cameron has other things to think about. One factor, as I reported for ConHome in November, it that it is in some ways even harder for a woman to enjoy, or at least tolerate, parliamentary life than it is for a man, so the attrition rate among women is higher.

Jenkin recognises the danger that the Conservatives will have fewer women MPs after May 2015, and insists that something will have to be done if this happens: “If we end up with fewer women MPs after the election I think the Conservative Party should be prepared to look at all the options and consider more radical measures, including all-women selections. Complacency isn’t an option.”

Her campaign has nothing to do with being trendy. The Conservatives used to get more votes from women than from men. Now Labour does. In his most recent Sunday Times column, Adam Boulton pointed to a YouGov poll which puts Labour ten points ahead among women, and only three among men. In Tuesday’s Financial Times, Helen Lewis argued that without women, David Cameron is fighting a lost cause.

There is a growing recognition even among Tories of a traditional outlook of the case for all-women shortlists. Lord Lexden has written, as Alistair Cooke, of the lead in this area which the Conservatives established when mass parties came into being:

“The imposition of tight controls on election expenditure for the first time in 1883 had overnight made political parties dependent on mass armies of volunteers. Women volunteers flocked to the Tory banner in far larger numbers than men, putting the Party way ahead of its Liberal opponents in this key respect” [the quotation is from Tory Heroine – Dorothy Brant and the Rise of Conservative Women, Sumfield & Day, 2008].

Something similar happened in the 1920s: by 1924 the Conservatives had over 4,000 women’s branches throughout the country, whose membership by 1928 amounted to nearly one million. The Labour Party, created by male-dominated trade unions, could boast nothing like this. For the Tories, only the last piece of the jigsaw failed to fall into place: there were 13 Tory women MPs in 1931, and still only 20 in 1992. Margaret Thatcher was a great woman, and in her way a great moderniser, but she appears to have inspired many more men than women to become parliamentary candidates.

I asked Lexden what needs to be done. He replied:

The Tories now suffer where once they triumphed. For years women flocked to support them. They were given the constituency chores, not the nominations. All modern Tory men now cringe at the way the talents of so many women were squandered by the Party for so long. It took Mrs Thatcher to show them the error of their ways, and after 2005 David Cameron went to great lengths to tell women that their place was the heart of the parliamentary party. But having been patronised and taken for granted for so long, they are reluctant to love an old Etonian: and his lamentable A list contained too many flashy younger women who were wrong for Westminster. Much more should have made of experienced women of solid worth, such as Pauline Latham who finally became an MP [for Mid Derbyshire] in 2010 at the age of 62 after years of labouring in the big society. There are many others who should now be placed on all-women shortlists, the only way the Tories can now purge their past misdeeds.”

Not all Conservative women agree with this. Tracey Crouch, MP for Chatham and Aylesford, wrote this Sunday in the Mail on Sunday:

“I disagree with tokenistic initiatives such as Labour’s all-women shortlists. They are patronising and self-defeating. If women are going to make their mark in politics, they have to do so on merit.”

Another Tory woman MP who opposes all-women short lists told me in a fury that “obsessing” about this issue was “really trite silly politics”. She is angered by “the rather irritating assumption that all women are the same”, and said some of the women who were elected in 2010 did not realise how “draining, tiring, exhausting and relentless political life is”.

A third Tory woman MP said that instead of all-women selections, she would prefer to increase the number of women by holding “genuinely open primaries like they have in the United States”, combined with “positive action”: mentoring and so on of the kind given to members of the A list.

Sarah Wollaston, the MP for Totnes, who was selected as a candidate in an open primary in which a ballot paper was posted to every constituent, said: “Clearly there’s a gender issue if less than one in five Tory MPs are women.” She believes that just as her previous profession, medicine, has been thrown open to equal numbers of women, so the Conservative Party can be. She dislikes all-women shortlists: “Every bit of me doesn’t like the idea of being the best woman for the job, not the best person.” But she reckons that a short period of all-women shortlists will be needed in order to avoid having the same conversation in ten years’ time.

A senior male Tory MP predicted that in the reshuffle expected after the European elections in May, the Prime Minister will promote more women to the Cabinet: he tipped Esther McVey and Liz Truss for conspicuous roles. But this MP added that as a matter of party management, Cameron will avoid any attempt to impose all-women shortlists before 2015. This is no doubt correct: in Tory associations, all-women shortlists would be about as popular as gay marriage.

But it is clear that Number Ten intends to exert greater and greater pressure to ensure that in constituencies where the sitting male MP retires before the next election, women and/or members of ethnic minorities have the maximum chance of being selected.

And it is also clear that opinion in the party is moving. I have spoken to a surprising number of Tories who until recently would have dismissed all-women shortlists as an abomination, but are now prepared to see that there may be a case for them.

Until recently, I found it hard to take this issue seriously. I do not accept the ridiculous notion that in order to represent someone in Parliament, one has to be identical to them. When people spoke in pious tones of the need for a diversity programme, I was inclined to suggest there ought to be one for Old Harrovians.

The unfairness that all-women shortlists would impose on men struck me as intolerable. A good local candidate who happens to be male could easily find himself excluded from a seat for which he would make an excellent MP.

But although these objections are correct, they are not conclusive. The Tory party has often stolen a march on a rival by stealing its clothes. When Disraeli widened the franchise, or Macmillan pressed ahead with decolonisation, many faithful Tories were shocked by what seemed to them like an abject capitulation to the spirit of a degenerate age.

After Cameron became party leader, the imposition of the A list of parliamentary candidates caused widespread discontent. Yet the 2010 intake of Tory MPs, men and women, is generally admitted to be one of the finest for many years. The quality of the men is higher than when they did not have to compete so hard against women to find seats.

The Tory party needs to widen its support and thereby increase its number of seats. It must show it can speak to and for the whole nation: something which Cameron and his closest allies, almost all of whom are men, and of a similar age and background, have often shown themselves singularly inept at doing. In particular, the way in which women can be expected react to particular reforms, or indeed to particular speeches, has tended to be overlooked, by men who do not know how to take this into account without making a particular effort. When I pointed out the absence of women from the inner circle in Downing Street, a loyal Cameroon suggested to me that Samantha Cameron could perform this role: a quite unrealistic and indeed unfair expectation to impose on her.

Miliband does not betray much sign of taking women seriously at the highest level. The Tories ought, however, to be able to trump him. Modernisation is a tiresome word. But if it means pragmatic adaptation to circumstance, it is indispensible. And as far as I can see (I can no doubt rely on readers of this site to correct me if I am wrong) the pragmatic thing for the Tories to do after the next election will clearly be to adopt all-women shortlists, for the limited period that these are needed to get a higher proportion of women into Parliament, and to re-establish the party on a wider basis than it has rested on since the last time it won a general election, which was in 1992. The alternative will be for the party to turn its back on the modern world and court extinction.