LONDON — THE quality of food and water has moved suddenly to center stage as a major issue in British national politics. Margaret Thatcher's ruling Conservative Party, under pressure from the Labour opposition and from Britain's partners in the 12-nation European Community (EC), has been forced to appoint a food quality watchdog to monitor food standards.
The prime minister's plan to privatize Britain's water industry is also drawing attention to the current quality of water for public consumption and to the possibility of falloffs when this prime resource moves out of the public sector in the next two or three years.
The food issue presents the most immediately worrying set of pressures on the Thatcher administration, now in its 10th year. Already one government minister has been obliged to resign following her suggestion that most of Britain's poultry industry was infected with the disease salmonella.
No sooner had Mrs. Thatcher begun to still the uproar among farmers, who denied the charge, than it was reported that another disease, lysteria, was being spread by unhygienic supermarket food.
Simultaneously, the Labour opposition and environmental critics began to attack the Thatcher plan to sell off a dozen publicly owned water authorities as part of the government's strategy of industrial privatization. Labour's health spokesman, Robin Cooke, has accused Thatcher of risking water quality, arguing that private companies will not put the public interest above considerations of profit.
A recent EC report on British beaches suggested that one in three swimming beaches failed to meet standards laid down by Brussels. The government accepted the report as accurate and has undertaken to clean up the beaches by 1993.
The prime minister's difficulties have not been helped by reports that Britain's population of rats, spurred by an unusually mild winter, has been increasing rapidly in cities where aging sewerage systems are beginning to break down. One government health official has warned that if steps are not taken to head off the problem, there could be outbreaks of cholera in Britain's larger cities.
In political terms, the arguments about food and water have provided new openings for the opposition. Government officials privately concede that official handling of the food and water questions has been muddled and confusing.
Labour leader Neil Kinnock, who has been widely criticized inside his own party for indifferent leadership, mocked the government for its ``feeble'' approach to food and water hygiene during a censure debate in parliament last week. In what many parliamentary observers describe as his best speech since becoming party leader, Mr. Kinnock used the issue to to dent Thatcher's reputation for political invincibility.