A campaign to force pubs to serve full pints of beer has won the backing of a Sussex MP.

Peter Bottomley, Tory MP for West Worthing, has signed a Parliamentary motion expressing concern that bar staff are legally permitted to sell a glass containing as little as 95 per cent liquid as a full pint of beer.

The early day motion claims the practice of selling short measures, whether intentionally or accidentally, costs drinkers £400 million every year.

The motion, signed by a total of 40 MPs, supports a drive by the Campaign for Real Ale (CAMRA) to push the Government to legislate for a pint to be defined as 100 per cent liquid.

CAMRA claims pints of beer are regularly served up to ten per cent short and says beer drinkers do not have the same rights as other consumers.

While customers who buy a litre of petrol or a pint of milk can expect to receive the full measure of what they have paid for, it says, beer drinkers do not have a legal basis for complaint if they are served slightly less than a pint.

CAMRA, which has launched a petition calling on the Government to end short measures, said a survey it carried out found one in four pints were more than five per cent under measure. It claimed short measures cost consumers £481 million a year - more than £1.3 million a day.

Mike Benner, CAMRA's chief executive, said: "It is a disgrace that up to a quarter of all pints served in the UK are less than 95 per cent liquid when the consumer is paying for a full pint every time.

"Labour promised to introduce legislation to end this unfair practice ten years ago and the continuing cost to beer drinkers from the Government's inaction has now run into billions of pounds."

Mr Benner added: "This is not just a problem that affects real ale drinkers. Lager drinkers and cider drinkers are being short changed too.

"It is time the Government met its promise and made sure pub goers get the full pint that they pay for every time. I would urge all beer drinkers that are fed up with being ripped off at the bar to sign CAMRA's Take it to the Top petition and help us make a difference."

CAMRA's petition is online at www.camra.org.uk Do you fell that pubs are ripping you off by not topping up your pint? Tell us your thoughts below.