Labour grossly over-deployed targets during its three terms in office: it ended up with more of them than William Tell.  They can none the less be a useful for tool for government, just as they can be for business, though there will always be debate about their number, degree and nature and at what level they are best set.  But there ought to be agreement on one point at least – namely, that it is almost always a mistake to write targets into law.

This is for the simple reason that Ministers should have the flexibility to change a target as new events take place and new information comes to light – or if they come to believe that the ideas that formed a target are out of date.  The Climate Change Act’s targets require us to decarbonise faster than our energy needs can reasonably bear.  The Child Poverty Act’s main target incentivises government to help those nearest the poverty line, not those further from it – in other words, the very poorest.

The Coalition Agreement commits the Government to enshrine its commitment to spend 0.7 per cent of Gross National Income on overseas aid into law.  This raises the question of whether the 0.7 per cent pledge is right in the first place, particularly given the scale of the deficit – still clocking in at £100 billion or so.  ConservativeHome is a pro-aid site, although we would like to see money directed away from multilateral institutions, a larger share going to child vaccinations, a greater focus on the provision of clean water and air, and further reductions in DFID costs – priorities that are shared by our readers.

It goes almost without saying that one can support all of this (in other words, be pro-aid) while simultaneously being sceptical about whether the 0.7 per cent target is a useful test of virtue.  But even if the target is desirable, it doesn’t follow that it would be right to write it into law – for the reasons that I set out earlier and previously.  Conservative Ministers have come to see that Tory backbenchers and activists hold this view strongly, and have wisely back-pedalled on acting on the pledge – which, like others in the Agreement, has been more honoured in the breach than the observance.

Until now.  Michael Moore, the former Scottish Secretary, has tabled a private member’s bill to put the 0.7 per cent target on to the statute book.  It is clear that one of his aims is to flush out David Cameron in relation to a commitment that he has signed up to.  Downing Street is duly making the supportive noises that it has left itself with little option but to make.  The Liberal Democrats are apparently threatening to block Bob Neill’s EU referendum bill if the Conservatives block Moore’s bill.

The Parliamentary manoeuvres may be obscure, but the politics are clear.  There is no clear gain to be made by writing the 0.7 per cent target into law, which there is no good case for in any event.  But there is a clear loss.  UKIP is on hand to remind voters that the Government has made the 0.7 commitment at a time of austerity.  And Conservative MPs will argue that if Ministers are willing to enshrine the aid commitment they should also increase, say, the defence budget.

Not so long ago, Number 10 was offering UKIP easy hits on same-sex marriage, wind farms, Europe…and aid.  It has closed down some of these hostages to fortune.  It must make sure that they’re not opened up all over again.  There are means of ensuring that Private Members’ Bills don’t reach the statute book.