Sarah Birch: Politicians' reputations are so low it doesn't matter what they do

The recent "cash for influence" scandal only adds to Parliament's disgrace. But if the public's response to last year's expenses scandal is anything to go by, MPs can take some solace from the fact that these new allegations are unlikely to further undermine their already sullied reputations. This, together with further evidence that Labour suffered more than the Conservatives from the expenses scandal, is the principal finding of new research into public perceptions of politicians' integrity.

Participants in an online study were asked questions about standards in public life, both in April, before The Daily Telegraph began publishing details of MPs' expenses, and again in September. What is most interesting is not the change that occurred over those five months but rather the virtual absence of change. The proportion of individuals who had a generally unfavourable view of politicians increased by only one percentage point: just under two-thirds believed standards were "somewhat low" or "very low" in April; just over two-thirds held the same view in September.

Worrisome is the possibility that the British public already held sufficiently negative views of their political leaders that the eruption of details of dubious expense claims did little more than confirm those views.

There perhaps comes a point when people become so inured to political misconduct that opinion bottoms out. The question then arises as to the consequences of such opinion for politics in general.

Delving deeper into the data sheds light on this question. Interestingly, the overall stability at the aggregate level masks significant change at the individual level. Almost a fifth of those surveyed had a more negative view of politicians in September than they had had in April, while almost a quarter had a more favourable view.

Those whose opinions of politicians worsened were broadly similar to other respondents in terms of age, gender, education, income and region of residence. The one common attribute of this group was that a disproportionate number of them were Labour Party supporters. Labour supporters made up just over two in five of those who registered a more negative opinion in the second survey but only a quarter of those whose views did not change or who saw an improvement in conduct. This indicates that Labour fared worse than Conservatives from the expenses debacle.

Just over a third said they believed Labour had been damaged the most by the revelations, whereas less than one in 10 said they thought the Conservatives had been hurt the most, and less than one in 100 identified the Liberal Democrats as the main party to suffer. (Just under half thought all the parties had been damaged equally).

It is too soon to judge exactly what the consequences of these changes in perceptions will be. Suffice it to say, the disillusioned and disaffected are more likely to waver in their habitual party loyalties.

Sarah Birch is a reader in politics at the University of Essex