Although President Karzai appeared to back down, activists say the revised law still contains repressive measures and contradicts Afghanistan's constitution and international treaties it has signed.

Islamic law experts and human rights activists say although the language of the original law has been changed, many of the provisions that alarmed women's rights groups remain, including: ''Tamkeen is the readiness of the wife to submit to her husband's reasonable sexual enjoyment, and her prohibition from going out of the house, except in extreme circumstances, without her husband's permission. If any of the above provisions are not followed by the wife, she is considered disobedient.''

The law has been backed by the hardline Shiite cleric Ayatollah Mohseni, who is thought to have influence over the voting intentions of some Shiites, who make up about 20 per cent of the population. Mr Karzai has assiduously courted such minority leaders in the run-up to Thursday's election, which is likely to be close, according to a poll released yesterday.

Human Rights Watch, which has obtained a copy of the final law, called on all candidates to pledge to repeal the law, which it says contradicts Afghanistan's own constitution. ''These kinds of barbaric laws were supposed to have been relegated to the past with the overthrow of the Taliban,'' a spokesman said.

A July opinion poll by US democracy group the International Republican Institute showed that although Mr Karzai was up 13 points to 44 per cent since the last survey in May, his closest rival, Abdullah Abdullah, had soared from 7 per cent to 26 per cent. If those numbers prove accurate, it would mean the contest would have to go to a second round run-off vote.