From Ms Jana Bennett

Sir: I am sorry that Carol Vorderman finds it so difficult to accept the reasons for her departure from Tomorrow's World, following her appearance in a new run of soap powder commercials ("Dear Auntie", 5 June). Indeed, she herself agreed terms which specified the BBC's right to end her contract in these circumstances.

When we offered Carol the job, we believed she could live with the quite usual contractual conditions which rule out commercials conflicting with the Tomorrow's World presenting role. When adverts first appeared, reflecting the Tomorrow's World style, we did "have a problem" with them - to use Carol's words. It was made clear this was a big problem - big enough to end the contract, which we did when we found more ads were to appear.

The BBC has always been clear about the issue involved; a programme such as Tomorrow's World has a long-standing reputation for first-class science and consumer journalism that must not be compromised. For 30 years the principle has been clear and simple: Tomorrow's World presenters don't endorse products.

As it happens, soap powders are subject to competing claims and can be subjected to scientific scrutiny. Tomorrow's World needs to preserve the ability to investigate the science behind soap wars and other issues with impartiality and integrity in order to keep our own brand name whiter than white.

Yours faithfully,

JANA BENNETT

Head of Science and Features

BBC Television

London, W12