The electoral triumph of Prime Minister Margaret Thatcher's Conservatives is already sending shivers through Britain's arts institutions, which are heavily dependent on government aid for survival. On Monday, the Royal Shakespeare Company--in spite of the huge success of two of its shows, "Les Liaisons Dangereuses" and "Les Miserables"--announced it may have to close down operations at its theatrical base in Stratford-upon-Avon, Shakespeare's hometown. Peter Harlock, the company's publicity director, said the RSC was "considering major surgery" to make up a deficit of 1.1 million ($1.8 million) caused by the Thatcher government's refusal to increase the company's grant and by a fall in box-office receipts in London. "It's a matter of closing in Stratford or in London," Harlock added. Two years ago the National Theatre, also complaining of inadequate subsidy, closed the smallest of its three London auditoriums to save money. Thatcher said during the election campaign that her party will proceed with its promise to amend the national Obscene Publications Act to cover television. Critics say it could turn the most liberal TV system in the world into one of the most prudish.