IT would not be surprising if the already stretched National Health Service was under further strain at the moment, as the scandal of MPs’ expenses continues to make our blood boil.

It is the talk of the country, and a long time has passed since a single issue generated such a reaction on our letters page.

But, as damaging as it is to the reputation of Parliament, the controversy has presented a perverse opportunity to those preparing to lead their parties into a General Election within the next year.

While Gordon Brown has struggled to appear convincing – particularly with his strangely grinning performance on YouTube – David Cameron yesterday seized the chance to display some leadership.

There is no hiding from the fact that all parties are in this mess together, and the Tories – with their claims for repairs to manors, moats, swimming pools and tennis courts – are up to their necks in David Heathcoat- Amory’s expensive manure.

The stench will take a long time to clear, but the British people are looking for positive action from political leaders to at least begin the process of rebuilding trust.

In one way, it is a huge embarrassment for Mr Cameron to have to order some Tory MPs to either repay public money or be kicked out of the party.

But in another, it is the clearest demonstration yet that a party leader fully understands the need for swift and decisive steps to be taken to lower the nation’s blood pressure.