What ever you think about gay marriage, supporting a firm commitment made to the electorate in both the Conservative Party manifesto and the coalition agreement to support marriage through fiscal policy should take priority over implementing a proposal that is not in the agreement.

The Prime Minister may be pro-commitment, but he doesn’t seem to think that the priorities of his own manifesto and the coalition agreement should take precedent over gay marriage. In his speech to the Conservative Party conference on Wednesday David Cameron reaffirmed that commitment in relationships was important, but rather than mention supporting low income couples through tax incentives to recognise the added value commitment, and by extension committed families, brings to society, he chose to highlight the forthcoming consultation on introducing gay marriage. The outcome of that consultation seems to have been determined already.

Moreover, the gay rights pressure group Stonewall estimates the cost of introducing such a proposal would be around £5 billion over 10 years. Not a cheap proposal, particularly when marriage and civil partnerships seem to be on the decline. To add to the problems with the proposal there are some in the LGBT community, particularly some lesbians who see marriage as a misogynistic hangover from past decades. So there is even a dispute within the gay community about the importance or validity of introducing marriage for the LGBT community.

It was Iain Duncan-Smith, the Catholic former leader of the Conservative party who reaffirmed the Conservative commitment to recognise marriage in the tax system in his speech earlier in the week. There is no doubt he was the appropriate man to do so. He is spearheading a benefits overhaul to make work pay, and pull people out of the benefits trap into dignified gainful employment. But if Cameron is so intent on supporting commitment, why leave the affirmation in support of marriage to Duncan-Smith?

The detail of the proposal put forward by the Conservatives was to introduce a transferable tax allowance, initially for the poorest families, that would see a partner who is not in work, for example because they are taking care of a child, to be allowed to transfer their income tax allowance to their in-work partner. This would mean that the work, the real work of raising a child, would be recognised at least in part fiscally by the state. It’s an eminently sensible plan, particularly because most women (and some men) want to stay at home for some time, while their child or children grow up. However, many are prevented from doing so because they are currently simply not able to afford that sort of luxury: the “luxury” of taking care of your own child’s early development.

Detractors of the proposal say that it would be insensitive to one-parent families. Perhaps that is true. For my money, single parents deserve more support than they are getting. Heroic single parents who are more often women than men should be applauded and supported. But leaving aside the single parent household, a large, if not the largest number of children living under the poverty line in the UK, belong to two parent households.

Progressives should be applauding the idea that the state might support the upbringing of children on or below the poverty line. Indeed, it would surprise me if most of the gay community would rather the coalition Government prioritise gay marriage over helping the poorest families children out of poverty. Doing this before implementing controversial proposals that some in the lesbian community find oppressive seems right whether you are gay or straight.

Cameron has chosen to pander to a perception that gay marriage is somehow a panacea to detoxify the Tory brand in the eyes of the liberal elite. He should focus on the pledges he has made to the electorate in the coalition agreement rather than help the ill-conceived secularist move to co-opt the rightful role of the church in determining the nature of marriage.