If the millions of people who go to a pub bought just one extra pint a month, the fortunes of Britain's locals would receive a huge boost, said campaigners.
The Campaign for Real Ale (Camra) said almost two out of five pub-goers were visiting a pub less often than a year ago, leading to a slump in beer sales.
Around 7.8 million pints were sold last year, compared with 8.4 million in 2010, with an average of 26 pubs closing every week in the UK.
The campaign will be stepped up at Camra's Great British Beer Festival in London, which opens today.
Chief executive Mike Benner said: "Around 32 million people in the UK enjoy a beer at least once a year, but the number of people drinking in pubs has been on the decline, contributing to an overall fall in beer sales.
"But with the price of a pint getting a much-needed duty cut in this year's Budget, there's never been a better time to get down the pub and help save the Great British pub. Just a pint a month extra is all it would take."