Payment, enforcement and collection of the BBC TV licence will come under the microscope from today, when the Corporation's governing body invites members of the public to comment on how the £139.50 levy is administered.

The BBC Trust review follows repeated complaints about the aggressive “It’s all in the database” advertising used by its collection agency and comes as public support for the fee, paid by 25.3 million households, is dipping.

Sir Michael Lyons, chairman of the BBC Trust, said: “This is an issue which arouses strong emotions because the right balance needs to be struck between ensuring compliance with the law and avoiding any disproportionate heavy handedness”.

In focusing on how TV licences are collected, the BBC hopes that it can avoid a broader debate about the principle of whether the fee should exist at all. However, it will be difficult to keep a lid on the debate as it holds an unprecedented public consultation on the subject.

Don Foster MP, the Liberal Democrat culture spokesman, described the enquiry as “a missed opportunity, which should also have asked questions that were outside the competence of the BBC to ask itself”.

He said the review should ask who should pay the levy, and whether alternative funding methods should be considered as technology changes.

“My view is that the TV licence is the least worst option but, when Britain goes fully digital in 2012, it might be possible to look at alternatives such as sponsorship and public funding for programmes that might not necessarily succeed in a commercial environment,” Mr Foster said.

Changing viewing habits are also undermining some of the basis of the licence fee. The levy falls due if somebody watches or records any live programming on a computer as well as a television, but cannot be charged if a person only watches previously aired programmes via the BBC and other websites.

John Whittingdale MP, the Conservative chairman of the Culture, Media and Sport Select Committee, said: “As people can watch television in different ways, using different devices, the flaws in the licence fee system get greater by the day.”

Nearly half the population is unconvinced that the BBC licence fee is fair. The levy raises £3.4 billion to fund BBC television, radio and online in the UK, but last month pollster Ipsos Mori found that 47 per cent disagreed with the statement that the licence fee represents “good value for money”.

The BBC estimates that 5.1 per cent, or just over one in 20 homes, evades the levy, and last year 413,000 people were fined by the courts for non-payment. The maximum fine is £1,000 for non-payment, although people can be jailed if they subsequently do not pay the fine. No figure for the number imprisoned is available, although one estimate suggests it is as many as 30 a year.

To discourage evasion, TV Licensing, the body that collects the fee, uses a marketing campaign in which a menacing voiceover tells viewers that every household in the country is monitored for compliance with the slogan that “It’s all in the database”. Jocelyn Hay, from the Voice of the Viewer and Listener, a media pressure group, said: “The tone of the advertising is very intimidating”.

People who do not own a television set — about 2 per cent of households — may receive strongly worded letters telling them they have not paid. Mr Whittingdale said: “If you think the advertising is aggressive, you should read the letters that are sent to people without a television. They behave like the Gestapo.”

The review opens today and will run until November 28. TV Licensing, the body which collects the fee, said it would contribute to the review, which it said reflected the “trust’s obligation to the BBC”.