Parliament has arguably had its worst week since the 1831 Reform Act. Whilst previous crises from Suez to the Great Depression have troubled the nation, they focused on policy or on individual leaders, not Parliament as a whole. The scale of today's problem is unprecedented and has inflicted grave and possibly lasting damage on the public's faith in Parliament and in every Parliamentarian. There have not just been a few bad apples playing the expenses game but almost the entire orchard.

The starting point for this Parliamentary crisis dates back over thirty years when Parliament approved the second homes allowance system by providing a tax free option to help MPs pay for the cost of running two houses. This approach prevented the need for a direct increase in salary which the public might have initially frowned upon. To give the system legitimacy, MPs had to submit receipts under a series of headings all linked to the upkeep of a second home, such as mortgage, council tax, utility bills, furnishings and repairs.

Bizarrely MPs were free to choose which home (London or the constituency) could be designated as the 'second home', regardless of what was said to the taxman, but as the entire system was not open to the public this did not seem to matter. Essentially it was seen as a way to compensate for the basic salary failing to stay competitive with yearly increases seen, for example, in the civil service, the armed forces or the private sector.

For many new MPs who do not enter parliament having already made their fortunes, the system can work in the way it was intended, paying towards the costs of running a second home where most of the allowance is used up by the interest payments on the mortgage or rent and utility bills.

For those wealthy MPs who do not have a mortgage, or for those who have finally paid it off, finding ways to maximise the claim for the allowance becomes harder. Failure to police the system properly has led to increasingly creative claims being made, from moat repairs to payments for garden manure, in order to harness this second homes allowance. The lax approach to its policing has led others to abuse the allowances even further by kitting out a property (essentially at the tax payer's expense) and selling the property only to start again somewhere else, a practice now referred to as flipping. Parliament therefore looks so discredited today, not just because everyone looks like they are on the take, but because no one stood up to try and challenge or expose the system.

It would, however, be fair to say that the vast majority do not go into politics to make money. If MPs are not paid adequately then Parliament will be dominated by those with personal wealth or union backing and that cannot be good for democracy. I therefore believe MPs should be paid a simple salary, determined not by MPs but by an independent body.

It is too early to say what damage this scandal has done to Parliament in the long term; the nation has every right to be angry with every one of us. No doubt the scale of that anger will become apparent when we all face the music at the next general election.