The Tory leader insisted that if he won the next General Election the Westminster "gravy train would well and truly hit the buffers".

Mr Cameron outlined his proposals for reform after kicking Alan Duncan out of the Shadow Cabinet for claiming that MPs were being forced to survive "on rations".

In a speech in central London, he admitted that saving money at Westminster would not solve the country's debt crisis.

But he insisted that politicians had to lead the "age of austerity" required to restore the public finances.

"Walk into a bar in Parliament and you buy a pint of Fosters for £2.10," Mr Cameron said.

"That's a little over half as much as in a normal London pub. And in the restaurants on the parliamentary estate, you can treat yourself to a 'Lean salad of lemon and lime-marinated roasted tofu with baby spinach and rocket, home-roasted plum tomatoes and grilled ficelle crouton' for just £1.70.

"That's all thanks to you - taxpayers' cash subsidising a politician's food and drink."

Cutting subsidies would save the public purse some £5.5 million a year, according to Mr Cameron.

Mr Cameron said: "We all have to eat, we all sometimes want a drink, there's nothing about this job that forces us to eat or drink any more than if we did something else.

"So with the Conservatives, the cost of food and drink in Parliament will be increased to match the prices normal people pay in cafes, restaurants and bars around the country."

He went on: "Last year, it cost £500 million to run Parliament. That's twice as much as it did in 1997. And has it really got twice as good?

"With the Conservatives, the gravy train will well and truly hit the buffers."

Mr Cameron said he would cut the ministerial element of pay by 5% after the election - equivalent to a £6,500 reduction on the Prime Minister's current £194,250 wage.

There would also be a freeze for the lifetime of the next Parliament, saving the taxpayer around £250,000 a year, he said.

The number of MPs would be cut by 10% for the following general election, from 650 to 585. That would save £15.5 million, according to the Tory leader.

“We’ve got far too many MPs in Westminster,” he said. “More people sit in the House of Commons than in any other comparable elected chamber in the world.

“So we will require the Boundary Commission to set out detailed proposals to reduce the number of MPs by 10% for the next General Election.”

Ministerial cars were sometimes “vital”, Mr Cameron said, but the number should be reduced by a third.

“If there is something that really annoys people it’s seeing politicians swanning around in chauffeur-driven cars like they’re the Royal Family,” Mr Cameron said.

“There is no need for 171 of these cars to be on hand for every government minister, whip - and indeed, myself.”

Mr Cameron admitted that the sums involved in running politics were a “pinprick” in terms of overall public spending.

But he added: “We’re determined to lead the country by powerful example and cut the cost of politics.”