Proposals for a transferable tax allowance for married couples and civil partners should be expected in the Autumn Statement, Chancellor George Osborne has said.
Once the Marriage (Same Sex Couples) Bill becomes law, and same-sex couples enter into marriages, the policy will also benefit these unions too.
Under plans being considered, wives and husbands who do not work and pay no income tax would be able to transfer part of their annual tax-free allowance to their spouse if their partner earns less than the higher rate of tax, which currently kicks in for people earning £41,451 or more.
“The government is committed to introducing it and I think you can expect to see it in the Autumn Statement,” Mr Osborne said to reporters at Westminster on Thursday afternoon.
Both the Chancellor of Exchequer and Prime Minister David Cameron have been under pressure from Tory backbenchers to introduce the measure, with some arguing it would help heal division in the Conservative Party following its split on equal marriage.
In their 2010 general election manifesto, the Conservatives said recognising marriages and civil partnerships in the tax system would “send an important signal that we value couples and the commitment that people make when they get married”.
The Tories said it would make four million married couples and civil partners £150 a year better off.
Labour opposes the idea and the Lib Dems were given a specific opt out in the coalition agreement which means they do not have to support it.
Earlier this month Deputy Prime Minister and Liberal Democrat Leader Nick Clegg called the proposals “patronising drivel that belong in the Edwardian age”, but David Cameron said he fully supported the policy.
The Autumn Statement usually happens towards the start of December.
It is used as a mini-budget by the Chancellor halfway through the financial year.