LONDON — Celebrities including James Bond stars Daniel Craig and Judi Dench and Harry Potter author J.K. Rowling urged the British government Wednesday to protect the “precious” BBC as it negotiates a new funding settlement. In a letter to Prime Minister David Cameron, the day before ministers set out plans for the public broadcaster's future, they warned that “nothing should be done to diminish the BBC or turn it into a narrowly focused market-failure broadcaster.” “The BBC is a very precious institution. Like all organizations, it has its faults but it is overwhelmingly a creative force for good,” it said. The open letter is also signed by presenters, actors and directors who have worked with the BBC, including David Attenborough, Michael Palin, Stephen Fry, former footballer Gary Lineker, chef Jamie Oliver and film director Richard Curtis. The government will publish draft proposals on Thursday on a new charter for the public broadcaster, which is funded by the television license, a tax on all British households. The BBC's funding has already been squeezed as part of Cameron's drive to reduce public spending and ministers have indicated they want to scale back some of its services, including the globally popular BBC website. Former BBC chairman Chris Patten, Britain's last governor of Hong Kong, on Tuesday accused the government of beginning the “destruction” of the BBC. He said a panel of industry experts appointed to advise on the agreement of a new charter next year were “assistant grave diggers” hired to help “bury” the broadcaster. Patten targeted much of his anger at a deal struck last week to force the BBC to pay for providing free TV licenses for the over 75s, saying it risked turning the broadcaster “into a branch office of the Department of Work and Pensions.” BBC director-general Tony Hall has stepped up his rhetoric in the debate, saying calls for a slimmed-down corporation were driven by people “with their own narrow commercial interests or ideological preconceptions.” “Our audiences are not asking for a significantly smaller BBC,” he said on Tuesday as he launched the broadcaster's annual report. He added: “It is part of what makes Britain, Britain. No other country in the world has anything like it — and the rest of the world envies the UK for having the BBC.”