X Factor judge Louis Walsh has put his star-spotting abilities at the disposal of Langdon, the London and Manchester charity supporting young Jewish adults with mild to moderate learning difficulties.

Addressing 400 people at a sell-out dinner at the Park Lane Hotel in London's West End, Walsh offered to judge a talent show for Langdon residents. And he called on the help of another celebrity guest, the singer Sinitta.

Walsh had been motivated by "an amazing speech" from Mandy Stanley, who told how Langdon in Manchester had transformed the life of her daughter Katie over a six-year period.

Langdon offers educational and supported living facilities to around 90 young adults. Its Manchester residential college provides courses for the 16+ from basic life skills to a range of nationally recognised qualifications.

In her welcoming remarks, dinner chair Carrie Rubin described Langdon as "a hidden treasure in our community", serving "youngsters who want inclusion in a world that is dismissive of them".

Langdon chair Barry Welck later told diners that the charity had a waiting list of 25 and there was no sign of demand abating. Projected expenditure for the year was £5 million and there was a £1 million shortfall after government contributions. A key commitment is The Quadrant, a £1.75 million Edgware scheme which will provide both accommodation and a drop-in community centre also open to those who are not Langdon clients.

Diners additionally heard from four residents, including Langdon College student Ben Weiner, 19, who said the skills and confidence he had acquired had enabled him to travel in support of his beloved Arsenal football team. His shout of "Up the Gunners" amused Portsmouth boss Avram Grant, who told the JC that Langdon's work was "more than important".

Another resident, Simon Houlton, confided that friends and family had noticed a positive change in him. "Thank you for giving me and everyone at Langdon the chance of a lifetime."

Walsh also took audience questions including showbiz friendships - he is in regular contact with Sharon Osbourne, "a good Jewish woman". And the most irritating celebrity he had encountered? "Bob Geldof. He's not here, is he?"

He said afterwards: "When I heard the Langdon stories, I got so emotional. It has been an inspiring night which gives me faith in humanity."

The X Factor connection was extended by a late appearance by Stacey Solomon, supporting "a very special charity" and leading residents in a rendition of the Hatikvah.

A record £450,000 was raised, most of which will go towards The Quadrant project.