Michael Lyons: We owe it to the viewers to protect the BBC licence fee

The BBC Trust is the guardian of the licence fee. Those are the words of the Charter – "the guardian of the licence fee". And that's not a duty we'll shirk.

This is not a matter of the BBC defending its own narrow interests. It's about fulfilling the Trust's duty to be guardians of the public interest in the BBC. That's another quote from the Charter.

In my book, "guardianship of the public interest in the BBC" includes seeing off opportunistic attempts to spend the licence fee on things that have nothing to do with the BBC's public purposes. Any proposal to spend any of the licence fee has to be judged against the public value it delivers. That's the acid test.

Let's not forget whose money we are talking about here. Not the Government's, not political parties', not other regulators' and ultimately not the BBC's. It's the public's money. It's licence-fee payers' money. People would do well to remember that licence fee payers give us their money in good faith, believing it will be spent on BBC services and content.

To suddenly tell them midway through the settlement that their money is being siphoned off, as some have suggested it should be, would be more than an act of bad faith, it would be tantamount to breaking a contract.

We know what the public would like to happen to any surplus. Ofcom's own research shows this clearly. They'd like their money back. As far as the Trust is concerned, returning any surplus to licence-fee payers is the benchmark against which any other proposal should be judged.

Some commentators have gone even further, speculating about monies beyond 2012 and the next licence-fee settlement. My view on this is clear. That's a discussion for the future and a decision for the government of the day.

When the process of agreeing the next settlement does begin it will require a measured look at the needs of the BBC, guided by the demands of the public. If we start off with questionable assumptions about where money can be apportioned based on an economic picture that will be three years out of date by the time the next settlement begins, we risk doing licence-fee payers a serious disservice.

Taken from a speech by the chairman of the BBC Trust to the Royal Television Society last night