Quotas to help "less exceptional" women succeed in business and politics should be introduced, according to Cherie Booth QC, the barrister. Booth, wife of the former prime minister Tony Blair, made the call at the Hay festival, where she also said that having a supportive partner was crucial to building a successful career.

"I am in favour of quotas. I think if we wait for it to happen naturally, I think it's going to take a long time," she said, adding that this was particularly true in politics and telling the audience that her husband's introduction of all-women shortlists for the Labour party was one of the things she was most proud about.

"There were more than 100 women MPs who did the job absolutely as well as the men. If a few women didn't do the job quite as well, believe me there are a lot of men who didn't either. I think the problem is, exceptional women will always succeed. But there are plenty of less-exceptional men who succeed.

"Until we get the less-exceptional women succeeding equally, we do not have full equality. We have to do something to accelerate that."

Booth, who is a barrister at Matrix Chambers in London and a mother-of-four, also said that many men who were high achievers in the corporate world had a supportive wife at home.

She added: "A lot of all this is actually about who you marry. Make sure you have a supportive partner."

Hilary Heilbron, another barrister who was appearing alongside Booth, said that she was not in favour of quotas, adding: "Aspirations yes, but I think if you have quotas I think people resent the fact that women get on, perhaps because it's not on merit."

"I also think women may resent it, because they haven't done it under their own steam," said Heilbron, who has written a book about the life of mother, Rose Heilbron, England's first female judge.