JOHN Major famously said that as soon as a Prime Minister crossed the No 10 threshold he, or she, began to lose touch with reality.

The events that have cost Maria Miller her job suggest that after four years in the Coalition hothouse David Cameron failed to gauge the sense of public and Parliamentary outrage that still exists over MPs' expenses. It shows the tremors from the 2009 earthquake that shook Westminster to its core are still being felt.

Last week, the Prime Minister, when asked about the Culture Secretary, sought robustly to draw a line under it; said she had promised to repay the money, had made an apology and so "we should leave it there".

But there was seething anger not least among the new Tory intake, who, with marginal seats, felt that they were being tarnished with an old brush.

Even when Cabinet ministers were called on to support their colleague, their reluctance was clear to see and they could only muster lukewarm support.

On Tuesday, Mary Macleod, Ms Miller's parliamentary aide, went on a media offensive to defend her colleague and accuse the media of a witch hunt. One theory is that this was a deliberate water-testing exercise, which showed how little support there was for Ms Miller.

Asked repeatedly if a grey-suited "emissary" from Downing Street had later that day contacted Ms Miller to tell her what to do, all the PM and No 10 would say was the decision to resign was hers. By not answering the question, they appeared to answer it and that Ms Miller had, in fact, been left in no uncertain terms what to do.

Time is beginning to run short for Mr Cameron to rediscover the pulse of public opinion; otherwise, next year it could be the public that tells the Tory leader to go.