The rate at which British pubs are closing down has accelerated to 31 a week and 3% of pubs in the suburbs have shut in the past six months, the real ale group Camra has warned.

Campaigners are calling for an urgent change in the law to make it harder for pubs to be demolished or converted to supermarkets and convenience stores.

The peak closure period was between January and June 2009 when 52 pubs ceased trading every week, and there are now 54,490 pubs left in the country.

At the start of its annual Great British Beer Festival, Camra has launched a campaign calling for a planning application to be required before a pub is demolished or converted to another use.

Pubs can currently be converted to a range of uses without planning permission. Camra says that in most cases communities have been powerless to save their locals.

Tom Stainer, head of communications at Camra, said: "Popular and profitable pubs are being left vulnerable by gaps in English planning legislation as pubs are increasingly being targeted by those wishing to take advantage of the absence of proper planning control.

"It is utterly perverse that developers are able to demolish or convert a pub into a convenience store or many other uses without any requirement to apply for planning permission. It is wrong that communities are left powerless when a popular local pub is threatened with demolition or conversion into a Tesco store."

Camra is urging more than 55,000 festivalgoers to lobby their MPs to support a change to the law. It is hoping for a repeat of its successful campaign to scrap the beer duty escalator, which automatically increased taxes by 2% above inflation.

Camra's week-long event features over 900 different real ales, ciders, perries and international beers across a total of 29 different bars. Nearly 50 MPs have already signed a parliamentary early day motion in support of closing the planning loopholes.

Stephen Langdon, one of a group of locals trying to save the Maiden Over pub in Reading, which has been threatened with conversion to a Tesco supermarket, said:"We found out just a couple of weeks ago that our valued local pub is shutting. My first thought on learning that Tesco were involved was that they would struggle to get planning permission for change of use. I was stunned when I learned that there was no requirement for this at all."

Camra said pubs support more than a million jobs and each contributes an average of £80,000 to its local economy each year.