Two MPs fall in a single day, one from each side. Julie Kirkbride's political career is over. Margaret Moran has gone too. In both cases the sequence was the same. First they gave long interviews attempting to defend their actions. Then they fell. One insisted she could have bought a new home, but chose to build an extension. The other had a home in Southampton that required investment for the sake of the family. Or was it the other home that was furnished to excess? I am beginning to lose sense of who claimed for what. My mind is drowning in images of duck houses, moats, massage chairs and the rest.

The glory of politics is its unpredictable shapelessness. Anything can happen and usually does. This though is getting both silly and sinister.

The silliness and the sinister dance together. None of it makes any sense. David Cameron tells some MPs to explain what they have done to their constituencies, the equivalent of being given a political death sentence in two stages. Kirkbride did not wait for the second phase. She knew she would be eaten alive at a meeting of activists and avoided the experience by standing down first. Others will do the same.

But Cameron's interest in local assertiveness is limited. He has told some MPs that the game is up, an act of centralised control deployed with limited consistency. Shadow cabinet members, especially close allies, seem to be safe. The grandees are doomed. Cameron hopes the clear-out will do him good, but it is not clear who will replace the rejects, and a lengthy process will lead to internal tensions. In the 1980s Neil Kinnock got credit at first for taking on internal troublemakers. The supporters of the troublemakers hit back and his party was dismissed as fatally divided.

On the government side the whip is withdrawn from some Labour MPs but cabinet ministers remain in place even if Gordon Brown deems their behaviour unacceptable. Some fear a visit to Labour's Star Chamber. Moran left before her interrogation. Others will also do so, though not all of them will have been as culpable as she was.

Now will Esther Rantzen stand in Moran's seat? She has said she will do so only if the voters want her. Does that mean she will only stand if she knows she will win? There seem to be limits to the bold energy of these newly fashionable independents.

The more orthodox political leaders have no choice but to seek the prize of ultimate disciplinarian. Voters want punishment. A colleague happened to be in Michael Gove's constituency the other day. He saw the MP in the high street engaged in an exchange with a few voters. Sliding past, he heard only one sentence. It was Gove trying to defend MPs' behaviour as "not the same as stealing".

MPs around the country are having similar conversations. Voters are starting to enjoy being angry. Lots of them have always hated politicians without specifying who they would put in their place. Now they have the ammunition. There is no interest in explanation. Look at how Margaret Beckett was howled down on the BBC's Question Time.

There seems little desire also in making distinctions between those who spent the admittedly generous allowances on second homes and the much smaller number who disgracefully fiddled the system, switching main homes and the rest. I briefly took part in a discussion on Five Live yesterday. One emailer offered to place Kirkbride in the stocks. That was restrained compared with responses being sent in last week in which public hangings were deemed a relatively mild proposal. One presenter was so shocked he refused to read them out.

Before I get put in the stocks, let me make it clear that I am not defending the greedy ones who fiddled the system. But I would add that it seems fairly arbitrary who the spotlight lands on next. I have received two calls from MPs terrified they would be on the front page of the Telegraph. Subsequently one appeared on page six, a relatively safe zone. Another has not appeared at all, but lives in fear that some mighty splash is being saved for a quiet news day and is consulting accountants from years ago to check that he was within the rules, a phrase that is not necessarily a route to salvation. The MP waits and wonders if his career is soon to be wrecked.

There are no rules about what is shocking and what is not. Claiming the full allowance to pay off mortgage interest is apparently acceptable, while spending a small portion on furniture is not. I still do not know why George Osborne has had to pay back cash for a taxi to London after a late night meeting in his constituency. Did we expect him to walk back?

There are some who see in the disproportionate frenzy some cause for optimism. I have written more than once in recent weeks that the anger could be a trigger for constitutional reform, although there is no direct connection. MPs elected under proportional representation might well have made the most of the allowances too.

Still, I am more pessimistic than optimistic about the consequences. It is no coincidence that some of the bloggers who report this story with particular glee are right-wing libertarians who openly despise politics. For those of who believe in the power of government to do good this is a depressing time. I find it difficult to see how elected politicians will be trusted to invest substantial sums in public services in the post-credit crunch future. If voters do not trust them with their expenses I dread to think how they would react to news of more spending, even though public services need funding as well as reform in the coming years.

I fear that the longer-term consequence of this saga will be rotting schools, useless hospitals and squalid trains, which is one reason why constitutional reform becomes more important. It might enhance the reputation of politics and politicians who otherwise will not be trusted for years to come. In the meantime Davina McCall might as well take an extended summer holiday. We have the equivalent of Big Brother already and cannot wait to find out who will be kicked out of the House next. Big Brother is safer than this.

s.richards@independent.co.uk