David Blunkett has accused Estelle Morris, the former Birmingham MP who quit the Cabinet admitting she wasn't up to the job, of setting back the cause of women in politics.
The former Home Secretary, who himself resigned twice from Tony Blair's Government, makes the claim in his tell-all diaries which have enraged colleagues.
Baroness Morris quit as Education Secretary in October 2002, when she was MP for Yardley in Birmingham, after 14 months in the post.
It followed a series of controversies including a dispute over A-level grades which led to thousands of papers being re-marked and delays in vetting teachers.
In his diaries, Mr Blunkett described Lady Morris's decision to resign as "suicide".
He wrote: "With decent advisers and a decent press office all of it could have been handled perfectly well.
"The worst thing was that she just declared herself as not being up to the job."
He added: "But sadly Estelle has done it, and has become the heroine of the moment - the honest politician, the person who says 'I'm not up to it', the person who says 'I liked my previous job but I don't have the strategic approach to manage this Department'.
"I fear that Estelle's resignation has done damage to the cause of women being promoted."
Mr Blunkett, who also served as Education and Works and Pensions Secretary, described the resignation as "extraordinary".
The book, which is expected to earn Mr Blunkett around £400,000, included claims that Tony Blair kept details of his heart condition secret and once threatened to sack Gordon Brown if he didn't publicly support the Iraq war.