This has been built on two key strengths: David Cameron's image as the most prime ministerial of all the leaders, and the Conservatives' reputation for economic competence.
The past month, especially the reaction to the Budget, has seen the foundations of those two pillars tremble - and the latest news that we are officially back in recession won't help.
Not only are people more worried about the impact of the Budget on them personally, but the proportion who think it will be bad for the country has doubled from 27 per cent to 53 per cent.
Overall, these are the worst ratings for any Budget since the mid-1990s. At the same time both George Osborne and Cameron have seen their personal ratings fall to their lowest ever, and worryingly for them, the falls were biggest among their own supporters.
Is it a surprise that the Government should be experiencing some mid-term blues? No. Should one month's bad ratings be a cause for panic? No. But should the potential damage to two of the key drivers of the Conservatives' reputation be taken seriously, particularly ahead of mood-defining local and London mayoral elections? Yes.