Programmes such as Channel 4 News air on analogue TV

Mr Gardam said it was becoming harder for public service broadcasters to risk making original programmes in the digital age.

In a speech to the Royal Institute of British Architects, he said: "At some stage the Department for Culture, Media and Sport might have to consider the lessons of... the allocation of National Lottery funding."

Channel 4 spends less than half the amount of money the BBC spends on BBC One.

Is there perhaps a thought here for government as it considers the quality of public space in broadcasting in the future? Tim Gardam, Channel 4 director of television

Mr Gardam said he was not arguing for the "instant abolition" of the licence fee.

But he said "the crunch" was coming with the proposed switch off of the analogue signal during the next 10 years.

"Will the economics of competition still deliver the diversity of public benefits they have done to date?" he asked.

"What incentive then will broadcasters have to carve out public space?"

Later, he added: "Is there perhaps a thought here for government as it considers the quality of public space in broadcasting in the future?"

The BBC provides value for money for the licence fee buyer BBC spokesman

According to the BBC's annual report for 2001/2002, the corporation spent £962m on BBC One and £410m on BBC Two.

In 2001 Channel 4 spent £426m on programme content.

Overall, the BBC spends £1,372m of its £2,591m budget on its national TV output.

Funding for television and radio in the regions and Scotland, Northern Ireland and Wales was £416m.

The Department for Culture, Media and Sport said it would not be looking at funding issues until a review of the BBC charter next year.

"This will provide an opportunity for issues of this kind and of BBC funding to be examined more fully," said a spokeswoman.

A BBC spokesman said: "The BBC provides value for money to the licence fee payer.

"How the licence fee is collected and distributed is a matter for the government."