Richard Desmond unveiled his Health Lottery yesterday with the bold claim that it was "the biggest brand launch this decade". White-suited figures in brightly coloured synthetic wigs patrolled the perimeter of the room in an attempt to match the hype with razzamatazz.

The new competitor to the National Lottery will debut this Saturday with the draw taking place on Channel 5, which is owned by Mr Desmond. In addition, the winning balls will be shown during a 50-second slot booked during The X Factor on ITV1. It will operate as a series of 51 lotteries, each representing a local authority area which will take it in turn to be a beneficiary of the draw. The media mogul is promising to generate a minimum of £50m a year for local health charities.

It came as some surprise that the face of this ambitious project to set the nation on a path to greater fitness would be the breakfast television presenter Eamonn Holmes, a man who, in an interview two years ago, said of his own physique: "You get to the point where you think it would be nice to get into a pair of jeans, or wear a T-shirt in the summer without worrying about man boobs." After bringing his ample girth to the microphone yesterday, Holmes said: "I have been chosen as the host of the Health Lottery – I'm as surprised as you."

But elsewhere on the platform – pointedly located at a private club in a former London hospital – there was unbridled enthusiasm for the venture.

"We want to be around for many, many decades," said the lottery's chief executive Martin Hall, dressed like Holmes in a shocking pink tie. "It's time to brighten up Britain, it's time to put a smile on people's faces." One way to do that, he claimed, was to do away with the notion of deferred jackpots. "Rollovers are bad. I don't want 'nobody' to win the top prize."

This differentiation was awkward, given that Sir Stephen Bubb, head of Britain's voluntary associations, has attacked the Health Lottery as "a disgrace" which will undermine the National Lottery's contribution to charities. The Health Lottery will pay 20p from each £1 ticket sold to good causes, compared to the National Lottery's 28p. Responding to questioning from the Daily Express, also owned by Mr Desmond, the Health Lottery chiefs explained that, unlike the National Lottery, the new venture would not spend money on sporting and cultural events and institutions such as the Olympics and the Royal Opera House, but solely allocate funds to health charities.

Mr Desmond, who is a reluctant public speaker, stood up briefly to state: "Just for the avoidance of debate, we won't be giving any money to the Opera House."

The Health Lottery has succeeded in attracting partnerships with the big supermarkets – across the social spectrum from Waitrose to Lidl – and will be promoted with an advertising campaign that features the actor Tom Baker, who will talk in the same tone he used to narrate the BBC comedy show Little Britain.

More importantly, the project will be backed by what Mr Desmond referred to as "our little group" – the Northern & Shell media empire that stretches from Channel 5 to the Daily Star and celebrity magazines including OK! and New!

Mr Hall, a marketer who has previously helped 118 118 to compete with BT in the field of directory enquiries, said of Northern & Shell's backing: "I have to say phenomenal. Absolutely phenomenal!"

He also declared the Health Lottery to be "infectious" – in a good way, presumably.

Q&A

Q. What are the prizes in the Health Lottery?

A. A £1 ticket gives you a chance of a £50 win for three matching balls, £500 for four and £100,000 for all five.

Q. Who will benefit from the proceeds?

A. 20p from each ticket sold will go to The People's Health Trust, an alliance of 51 local health lotteries from across Britain under the overall chairmanship of Jennie Popay, a professor of sociology and public health at Lancaster University.

Q. So if good causes stand to benefit, what's not to like?

A. Critics believe that the Health Lottery's 38,000 terminals could take money from the National Lottery, which gives more per ticket (28p) to good causes.

Q. What's in it for Richard Desmond himself then?

A. Following his successful launch of "Big Brother" on Channel 5, the Health Lottery will provide further profile-raising content for the network and for Desmond's print media empire. All of these brands stand to gain from association with a good cause – as indeed does Desmond, who is already a big charity donor and could end up with a knighthood if the Health Lottery takes off.