According to figures released by the British Beer & Pub Association (BBPA), overall beer sales in both the off and on-trade are at their lowest level since 1969 with the total beer market falling 22 per cent since its peak in 1979.
Brewers say they are also facing a further profit squeeze with the rising prices of barley, malt, glass, aluminium and oil.
Rob Hayward, BBPA chief executive, said: "The time to support our national drink is long overdue. We are calling for government policy to encourage and support Britain's businesses.
"British brewers and beer are of world renown. But our efforts to remain competitive are being undermined by a tax policy that is eroding the foundations of our business. We need a tax freeze and that is what we are calling on the Chancellor to deliver."
Beer duty has increased by 27 per cent over the last 10 years, compared to 16 per cent on wine and 3 per cent on spirits.
Brewers and the BBPA have written to MPs today saying that freezing taxes on beer would make the drinks market more competitive and save Britain's national drink.
For more information on the UK beer market, see the OLN Beer Report 2007.