Rush for gender equality with top judges 'could have appalling consequences for justice'

In other remarks, Lord Sumption, who is also an award-winning historian, called for “radical” reforms to reduce legal costs and spoke of his concern for the “terrible” plight faced by young Londoners seeking to buy homes.

His most striking comments, however, were on diversity as he warned that equal representation for women in the judiciary would take decades to achieve. “These things simply can’t be transformed overnight, not without appalling consequence in other directions,” he said.

Lord Sumption added: "One has to look at the totality of these problems and not simply at one of them. The lack of diversity is a significant problem, but it isn’t the only one.”

“It takes time. You’ve got to be patient. The change in the status and achievements of women in our society, not just in the law but generally, is an enormous cultural change that has happened over the last 50 years or so. It has to happen naturally. It will happen naturally. But in the history of a society like ours, 50 years is a very short time. “

Warning that the judiciary and the quality of British justice was “a terribly delicate organism”, Lord Sumption added: “We have got to be very careful not to do things at a speed which will make male candidates feel that the cards are stacked against them. If we do that we will find that male candidates don’t apply in the right numbers. 85 per cent of newly appointed judges in France are women because the men stay away. 85 per cent women is just as bad as 85 per cent men.

“What we have in this country is a long cultural tradition which is genuinely based on public service, people feeling that at the end of a successful career at the Bar, that [becoming a judge] it is something that you ought to be willing to do. That’s a terrific public asset.

“It’s a tradition which you can destroy very easily and never recreate, not without waiting for a very long time. It would be very unfortunate.”

Lord Sumption, who joined the Supreme Court in 2012 after a career as one of the country’s most highly paid barristers, emphasised that he supported female equality and wanted to see “hidden barriers to the progress of women” removed.

But he warned that the most serious was a “high attrition rate” among female lawyers that was “particularly difficult” to address.

He added: “The Bar and the solicitors’ profession are incredibly demanding in the hours of work and the working conditions are frankly appalling. There are more women than men who are not prepared to put up with that. As a lifestyle choice, it’s very hard to quarrel with it, but you have to face the consequence which is that the top of the legal profession has fewer women in it than the profession overall does.”

Lord Sumption said change was occurring and would eventually “result in gender being a wholly random matter, so it will be either 50/50 or somewhere round there.”

But he cautioned: “That can’t be done straight away. If we were to pass a decree that every alternate judicial appointment was to be a woman, it would still take us 20 years to get to 50/50. Nobody is proposing that.”

Official figures show that 21 out of 106 High Court judges are female and that there are eight women among the 38 Court of Appeal judges. That amounts to around one in five female judges in both cases. The Supreme Court has only one woman, Baroness Hale, on its bench. The overall proportion of female court judges is just over 25 per cent.

Some critics have claimed that traditional “old boys’ networks” are part of the reason for restricting female progress in the Bar and on the bench.

Lord Sumption said, however, that while he obtained his pupillage in the 1970s via a friend of his father, such claims were now “rubbish in both cases”.

He added: “The Bar is a very meritocratic profession.The same applies at every level, for getting silk and going to the Bench. I was a judicial appointments commissioner for six years. I’m sure we made mistakes, but we went to an enormous amount of trouble.. to choose the best candidates possible.