Writing in the Daily Mail, David Cameron explained how the £1,000 marriage tax break would work:
From April 2015, if neither of you are higher rate taxpayers, you will be able to transfer £1,000 of your tax free allowance to your spouse.
In effect, if you pay the basic rate of tax and your partner doesn't use all of their personal allowance, you'll be able to have some of it. Most couples who benefit will be £200 a year better off as a result.
And of course this will be true if you’re gay or straight – and in a civil partnership or a marriage.