The protest is being organised by Block Telethon, a group of disabled people who argue that, well- intentioned though the show may be, it does more harm than good for disabled people by reinforcing negative stereotypes.
'It portrays us as tragic, pathetic victims who long to be non- disabled, or plucky heroes who deserve a pat on the head for triumphing over adversity. Well, we've had enough of it,' says Alan Holdsworth, a founder member of Block Telethon, who also sits on the executive committee of the British Council of Organisations of Disabled People.
Mr Holdsworth, a musician and poet, led pickets at both the 1990 Telethon and last year's BBC Children in Need, when he was arrested. He expects this year's protest to be the biggest yet, attracting up to 1,000 disabled people.
Rachel Hurst, who runs the campaign group Disability Awareness in Action, says: 'The horrendous stereotyping in programmes like Telethon is one of the greatest obstacles we face in our struggle to be recognised as normal human beings. It is one of the reasons why we continue to be oppressed and discriminated against.'
Disabled people are not the only ones Telethon aims to help - disadvantaged children, old people, single parents and other groups also receive donations. But the producers acknowledge that it is people with disabilities and their carers who feature most prominently and provoke the strongest public response.
By making them 'objects of charity', Ms Hurst argues, the programme humiliates disabled people and hinders their quest for greater integration. 'The notion of groups of able-bodied people around the country being encouraged to raise money for another group they can then dissociate themselves from is both repellent and dangerous,' she says.
'What Telethon and programmes like it should be doing is encouraging able-bodied people to make disabled people members of their pubs and clubs, to employ them, let them into their schools, give them reasonable access to public places. We need that much more than the money raised from donations - which doesn't amount to a great deal anyway.'
The 1990 Telethon raised pounds 20m, a quarter of which went to disabled people's groups. If the total were shared between every disabled person in the country, they would receive pounds 3 each.
More damaging, critics say, are the short appeal films that punctuate Telethon, based on individual case histories and designed to tug at the viewers' heartstrings - and purse strings. They are often 'offensive, intrusive or patronising', the protesters maintain. They particularly disliked one during the last Telethon featuring a man with a rare skin condition who was shown partly naked.
The appeal films tend to show disabled people being helped to do things by physiotherapists and carers rather than doing things for themselves, which encourages able-bodied people to see them as a helpless burden on society, the campaigners say. Celebrities and presenters are accused of compounding the damage by patronising disabled people.
The producers of Telethon are acutely aware of disabled people's objections and have taken steps to rid the programme of stereotypes and images that might be offensive. 'We have tried to change over the years, and our awareness of the issues has increased a hundredfold,' says Alan Boyd, of TVS, the show's director.
Telethon has produced a 'disability etiquette guide' for people working in television, full of advice ranging from language - 'never use 'handicapped', 'victim' or 'afflicted by' ' - to how to interview a person in a wheelchair. The 15 ITV companies have held disability awareness workshops designed to teach producers, directors and technical staff working on Telethon to view disabled people more positively.
The result has been a 'perceptible change' in the quality of the appeal films submitted by the companies, says Martin Lucas, the producer responsible for that aspect of Telethon. 'The sensibilities have shifted; there's less pathos and more genuine understanding and respect,' he says.
Mr Lucas, who is himself disabled, has introduced a new strand to the Telethon aimed at raising consciousness rather than money. 'We will have disabled people talking about how they deserve the right to work like anybody else, the right to proper training, integrated schooling, independent living, reasonable access and the right to be sexual beings and have a family life.'
Mr Lucas says he has 'the utmost sympathy' with many of the aims of the anti-Telethon lobby, which include getting more disabled people on to mainstream TV, especially in drama, soap operas and the news.
But banning the show is not the answer, he says. 'At the moment, it represents one of the few chances disabled people have to get exposure on TV. I see it as a great opportunity to slip the knife in, to be subversive. If we can work within it to change the way people view us, then that's all to the good. It is only then that we will start to be included on TV in other ways.'
'Telethon '92' starts at 7.30pm on Saturday 18 July and finishes at 11.35pm on Sunday 19 July.