The self-made millionaire said some senior women were "more conscious" than men of the problems childcare poses for female employees.

Sir Alan, executive chairman of Amstrad and Viglen, told The Times: "There are women employers who are more ruthless than men.

"They are more conscious of not employing other women because they feel they're not going to get the value of work out of them."

Sir Alan spoke out about working women and childcare ahead of his new series of BBC1's The Apprentice, which is starting its fourth season.

He also said women should be open about their plans to have children and how they expect to care for them.

"You pay a person a salary and they cut their cloth accordingly," he said.

Sir Alan, known for speaking out about the problems faced by women in business, said last month that equal opportunity laws could make it harder for female candidates to get jobs.

He criticised rules that stop bosses asking whether job applicants plan to start a family.

Sir Alan denied he endorsed discrimination, but said women should be given the chance to explain how they would cope with balancing a job and childcare.