If you want to see a fearful expression, talk to senior coalition members about shifting patterns of support among women voters. Call it a cold-sweat, or a premature onset of mid-term jitters -- they are distinctly, indisputably on edge. Which is odd, at least on the face of it, given that the Conservatives -- if not their Coalition partners -- are currently polling at broadly similar levels of support to the last election. So what explains this onset of nerves?

To help answer that question the Resolution Foundationasked Ipsos MORI to undertake a detailed analysis of voting intentions in the first half of 2011 compared to the 2010 general election result. The findings are striking - and they reveal one thing beyond doubt: when it comes to support amongst women, the Coalition does have reason to be anxious, even if some of the recent comment on this issue has been overblown.

_{Source: Ipsos MORI
Base: 10,211 GB adults aged 18+, 19 March-5 May 2010; 7,176 GB adults aged 18+, January-July 2011}

Of course, it's important to tread very carefully when talking about the so-called women's vote (itself a meaningless phrase -- when do you ever hear politicians talking about the "men's vote"?). Sensible generalisations can rarely be made about half the electorate. Nor do the headline figures stand up the contention that a dramatic gender gap in electoral support has opened up. Most people, regardless of gender, care about the same issues -- jobs, inflation and living standards; crime; immigration and the NHS.

And the impact of age, class, occupation and geography often trumps that of sex in explaining differences.

But make no mistake, and despite all the caveats, some shifts are occurring. It's well established that at the last general election, women were on average more likely to vote for the Liberal Democrats than men (26 per cent v 22 per cent), as well as Labour (31 per cent v 28 per cent).

Less understood and more interesting are the staggering variations that exist underneath these headline figures. Women aged 25-34 were more likely to vote for Labour than the Conservatives (11-point lead) whereas C2 female voters (of all ages) were dramatically more likely to back the Conservatives than Labour (by a remarkable 17 points), fully reversing Labour's towering 18 point advantage among the same group in 1997.

Following the 2010 election, during the early and easy days of the Coalition, Tory support climbed among women, reaching a commanding 45 per cent in one poll at the end of 2010, hovering just below 40 per cent in others, compared to around 34 per cent of men. Since then the Tories' lead amongst women has fallen, dropping below that of men in many polls.

Perhaps more noteworthy is that overall levels of 'approval' for the Coalition have fallen to 25 per cent among women, 8 per cent lower than for men. Just 13 per cent of women feel that the Conservative Party is the party which is closest to women and best understands and reflects their views; plummeting to 7 per cent for the Lib Dems. When it comes to their personal ratings both Cameron and Clegg have a deficit of 6 per centamongst women compared to men. No wonder Downing Street strategists -- both Conservative and Lib Dem -- are jumpy.

Given that these headline findings about "women's attitudes" inevitably conceal more than they reveal it is vital to get a more granular account of changes in political support amongst different groups of women. To make a start at this we can break down levels of support in 2011 by age and social class compared to those in the 2010 election (admittedly still very broad and crude categories).

The results are intriguing. In terms of social class we see that both the Tories and Lib Dems have haemorrhaged support amongst C2 women (typically skilled manual workers), often key voters in swing seats. In contrast the Tories have actually gained support amongst female AB voters (professional and managerial), and seen their support hold steady amongst male C2s.

The Lib Dems have performed even worse amongst female ABs than other classes. They also show that the proportion of women aged 18-24 who support the Tories has declined from an already low 30 per cent at the General Election to just 18 per cent in 2011, while support among the same group for Liberal Democrats has collapsed from 34 per cent to just 8 per cent, meaning the coalition has succeeded in losing 38 per cent of its support among this group. To be clear, male voting intentions have also moved in the same direction but to a lesser extent.

_{Source: Ipsos MORI
Base: 10,211 GB adults aged 18+, 19 March-5 May 2010; 7,176 GB adults aged 18+, January-July 2011}

There are plenty of potential explanations for these shifts -- though very little hard evidence as to which is most telling. Much of the media comment earlier in the year focused on some of the Coalition's unfortunate symbolic moments which have pierced the public consciousness -- from David Cameron's "Michael Winner moment" during PMQs to Ken Clarke's linguistic contortions over rape.

More recently the focus has switched to the way in which the deteriorating economic situation is impacting on many women, particularly those on low-to-middle incomes. Over the last quarter unemployment increased by 38,000, with 21,000 being women. Female unemployment had already risen by 76,900 over the last year - with the number of women out of work now 1.05 million, the highest since the spring of 1988 - and the forecasts are that female unemployment will continue to rise as women are disproportionately suffering due to their higher concentration in the public sector. Qualitative research suggests that women are more inclined to be pessimistic about the economy and feel they are more likely to lose out as a result of cuts. On top of this, particular groups of women -- such as those in their 50s -- are being faced with major shifts in their pension age that they weren't anticipating, causing real concern.

As Ben Page of Ipsos Morri says, "Women, and working class women in particular, are shifting away from the government, reflecting the fact that they are hardest hit by both the recession and cuts in public spending."

Given the wider economic context of falling wages and rising prices you might think it is a uniquely dumb moment to be making it more difficult for households to sustain two people in work by withdrawing childcare support. But that is what is happening.

As leading welfare expert Donald Hirsch has pointed out, April's cut in support from 80 per cent to 70 per cent of eligible childcare costs may not sound all that much to some people - including ministers. Not, that is, until you work out what it means for the many families with young children struggling on low wages who will be most affected. A couple with two young children paying out £200 a week in childcare will need to find an extra £20 a week to recoup this lost tax-credit income. That's £1,000 a year of post-tax income.

What does this imply for their pre-tax earnings? To recover the full £1,000 they'd have to earn an extra £3,700. Fat chance. Many women are likely to conclude that work simply doesn't pay.

Some straws in the wind suggest these changes may be starting to take their toll. A poll out last week reported that the high costs of childcare were leading high proportion of low-income parents to consider reducing their hours or give up work; whilst another recent report found the number of families getting income from a second salary has fallen from 36 per cent in May this year to 30 per cent in August. Median monthly net family income dropped by two percentage points over the same period - the main determinant being an 8 per cent drop in women's incomes while men's incomes rose.

And now the mistake on childcare policy looks set to be compounded. As was first flagged up in spring, and has been back in the news over the summer, there are further changes in the pipeline - as childcare support gets integrated within the universal credit, making employment even less worthwhile for many working mothers. (Note that when it comes to childcare it is low-earners who will bear the brunt of reduced support, the tax-relief going to higher-earners via childcare vouchers remains unscathed by the Coalition).

Stir into this cocktail the proposed abolition of Child Benefit for higher rate tax payers scheduled for 2013, the most aggrieved victims of which will be women in single-earner households living on just over £40,000. Their outrage will be given added piquancy if this coincides -- as is widely tipped -- with the abolition of the 50p tax rate, benefiting the richest 1 per cent of earners, the majority of whom are, of course, men.

Clearly all this gives Labour a lot to aim at -and there has been no-shortage of tactical attacks. Labour's polling position has strengthened, especially among C2 women. But they are yet to convert improved poll ratings based on protest into solid support, and still need to grapple with the deeper sociological and economic changes in UK society that will reshape the nature of the electoral coalition required to win in 2015.

For the Liberal Democrats there is both extreme risk and a glimmer of opportunity. The risk, of course, is that their shattered support among working women continues to act as an anchor on their overall levels of support as the party soaks up blame for unpopular decisions. The opportunity as they see it is to rebuild some of their bedrock support by differentiating themselves on issues thoughts to appeal to key groups of women. Senior Lib Dem strategists are seized of the need for this and see "our catastrophic loss of support amongst working women, especially C1s/C2s, as perhaps our biggest electoral challenge", more so even than the collapse amongst 18-24s who tend to vote less. "If we are not seen as a party of mainstream working women we are nowhere."

Expect senior Lib Dems to use their Conference to package their flagship policies on tax-allowances, part-time students, and shared parental leave to make this point. And don't be surprised to see them playing up what they see as the social conservatism of both main parties -- whether it be Nadine Dorries on the right, or the mis-firings of Blue Labour on the left, as evidence that they are more in tune with the mood of mainstream women.

The reality, though, is that in times like these, economics tends to dominate. As senior Lib Dems concede, the party has little chance of getting a hearing if the Coalition's agenda -- particularly on issues like childcare - is seen as another threat to living standards. Which explains why they view further proposed cuts to childcare with escalating levels of anxiety, and why Nick Clegg has inserted himself in key Whitehall discussions on the future of the childcare tax-credit.

Clegg will no doubt find that fights like these -- with spending implications - are the toughest. Unfortunately for him they are a key litmus test for his ability to improve the lives of low-to-middle income working mothers. Cuts to childcare support are hitting working women where it hurts at the worst possible moment. For their sake, as well as his own, this is a battle the Lib Dem leader needs to win.