So far she has been singing while doing the washing — now Lucinda Belle can leave her south London launderette after landing a £1.25 million record deal.

Belle, 36, who has been likened to Norah Jones and Madeleine Peyroux, is putting her family cleaning business in Balham High Street up for sale to concentrate on being a recording artist.

While carrying out her main job running the launderette, she worked as a session musician for acts including Pet Shop Boys, Rufus Wainwright and Annie Lennox. But last year Fearne Cotton spotted her working as a backing singer and harpist for Robbie Williams at the BBC Electric Proms.

The Radio 1 DJ invited Belle on to her show, which brought her to the attention of major label Universal. The company, which has Take That, Cheryl Cole and Amy Winehouse on its books, signed her up to a five-album deal. Belle's first release will feature her band The Lucinda Belle Orchestra — comprising harp, harmonium, melodica, strings, horns, double bass, drums, ukulele, clarinet and guitar.

She said she loved the launderette and it was a hard decision to sell. “It's been in my family for 40 years and was passed down by my grandfather, but I don't think I'm going to have time to be there any more. This is what I really want to do. As long as I can remember I've been trying to get a record deal.

“It's not a good time for running a launderette anyway. The price of gas has gone up.” But she will continue being a part-time singing teacher. Belle, who lives in Ladbroke Grove, first played the harp at the age of six. “I fell in love with it straight away,” she said.

Her debut album is expected to be released in May.