The Scottish National Party will scrap the £200 a year married couple allowance if it wins the referendum vote in September 2014.
The £700m ($1.1bn, €835m) scheme, which was announced in the government's autumn statement, comes into force in 2015 and will allow lower earners to transfer up to £1000 of their unused tax allowance to their spouse.
SNP MP Eilidh Whiteford attacked Cameron's policy on the grounds that it was inherently biased towards men and said that only 15% of women would benefit from the scheme. The £700m price tag could be better spent elsewhere.
Whiteford said: "The UK government marriage tax break is short-changing women. The policy reinforces other measures that discourage 'dual earning' couples, by making those who benefit lose if their partner takes a job for more than a few hours a week.
"The Women's Budget Group has recognised that it will dissuade women from going back to work because the husband could lose their allowance if his wife gets a part-time or low-paid job that takes them over the earnings threshold.
"Westminster's tax-breaks which only benefit the traditional nuclear family shows how out of touch the UK government is," she said.
Scotland's Future, the Scottish Government's White Paper on independence, states: "This scheme will effectively discriminate against many families where both partners work, unmarried couples, widows, widowers, single parents and women who have left abusive relationships.
"Under the proposed system, around two-thirds of all married couples will not benefit and analysis of the proposals suggest that couples with children are much less likely to receive the full allowance and that many low and middle income married couples are likely to have much of the tax break clawed back through the benefits system."