The Guardian’s monthly ICM poll, published today, asks a couple of intriguing questions.

For a start, we discover where Lib Dem supporters perceive they sit within the class system (however self-defined) – 50% say they are middle-class, and 48% that they are working-class. This compares with 38% middle-class to 61% working class for Labour; and 56% to 39% for the Tories.

(Slightly bizarrely, it turns out the Lib Dems have more supporters who identify themselves as upper-class (2%) than the Tories do (1%); the poll’s margin of error may explain that finding.)

But the ICM/Guardian question which interested me most was this one: ‘Would you personally support or oppose the introduction of a tax break for married couples with children?’

Overall, 65% of voters said they supported the measure, just 29% opposed it. How does this break down, according to which party voters support? Well, among those who said they’d vote Lib Dem, 59% said they supported the measure, while 38% said they opposed it – a net 21% support for married couple tax breaks. This compares with net 42% support from Labour voters, and net 46% support from Tory voters.

Net support for married couple tax breaks according to party:
Lib Dems: 59% / 38% = +21% net support
Labour: 70% / 28% = +42%
Tories: 69% / 23% = +46%

So Lib Dem voters are less likely to support tax breaks for married couples; while Labour/Tory voters have broadly equivalent views.

However, that still leaves a seemingly tricky issue for the party: while the Lib Dems are opposed to the policy, our voters appear to like it.

Well, up to a point. I find the question ICM posed to be a simplistic and misleading one: do you support or oppose tax breaks for married couples? Many people will have heard the words’ tax break’ and – in the current hard-pressed economic climate – said yes, please. What ICM didn’t offer to those polled was a balanced question, showing that there’s a real choice at play here – for instance, they could have asked:

‘Some people say tax breaks for married couples are an important symbol of government support for marriage, while others say government should focus on lifting children out of poverty regardless of whether their parents are married or not. Which of these views do you support?’

What results would ICM have found if they had polled the public with this question, a question which actually reflects the choice before politicians when deciding how to target taxpayers’ money to the maximum benefit of society? My guess is they would have found far fewer people supporting the Tories’ policy of marriage tax breaks than was revealed by this poll.

Especially if it were pointed out – as Lib Dem research has discovered – that under the Tories’ married couple tax break plans:

• fewer than one in seven of the children living in poverty in the UK will benefit from Tory plans to recognise marriage in the tax system. Only 14% of children in poverty live in couple families where just one parent works full time;
• it will be no help to the 230,000 children living in poverty with one parent who juggles work with caring for them;
• it will be of no help to the 29,000 children who live in poverty with both parents who both work full time; and
• four out of five working age adults that live in poverty would not benefit from married tax allowance: 46% of adults in poverty are single.

The simplest, fairest way to help people out of poverty? Stop making the poorest pay tax – just as the Lib Dems propose. Unfortunately, ICM didn’t poll the public’s opinion on that policy.