Once of no fixed abode, rapper finds a place on Mercury Prize shortlist

Speech Debelle edges out former favourite Lily Allen to pick up nomination

A young female rapper who found much of the inspiration for her debut album while listening to the stories of her fellow homeless residents in south London hostels is in the running for the music industry's most prestigious prize.

Speech Debelle was 19 when she was asked to move out of the family home in Crystal Palace, embarking on a four-year odyssey through the druggy underbelly of the capital's dispossessed. What emerged was Speech Therapy, one of seven first albums to make it on to the 12-strong shortlist for this year's Barclaycard Mercury Music Prize.

Debelle is among five female artists in the running for the annual award which has become as famous for the big names that are left out as those that are included. This year Lily Allen, the early favourite, saw her second album It's Not Me, It's You, follow in the footsteps of her first and fail to beat the cut. So too for the highly fancied Doves, White Lies and Little Boots, all of whom will be elsewhere when the gong is handed out at a boozy award ceremony in September.

Instead it falls to Florence Welch, better known as Florence and the Machine to assume the role as new favourite, an honour she shares with Kasabian, who finally make it on to the shortlist for the first time with their third – and least commercial – album to date. Bat for Lashes, aka Natasha Khan, is the only artist to have featured on the list before, as her second album Two Suns follows the first by gaining a nomination.

But Debelle's troubled back story and glowing comparisons with Lauryn Hill and Tracy Chapman make her the most intriguing candidate even if she fails to defy the long odds and take the prize.

"I think it deserves to have this because it is a good album and all the musicians are excellent and everyone had an understanding of what we were trying to achieve from the outset," she told The Independent.

The Mercury, which lays claim to receiving the most media coverage of any European arts award, has in the past delivered massive sales boosts for artists, some of whom were virtually unknown before their inclusion. Led Bib, whose third album Sensible Shoes is included as the jazz entrant is now 10/1 to win, despite having sold just 600 copies worldwide.

This year's rank outsiders however are Sweet Billy Pilgrim, who recorded Twice Born Men on a laptop in a garden shed. Guitarist and songwriter Tim Elsenburg said he was as surprised as anyone to hear the news.

"I was at work, fitting a toilet seat in Farnham, when I heard about the nomination," he said.

"The two realities sort-of collided and time and space went funny for a bit, and I may have just repeated a certain expletive at regular intervals for the first few minutes."

The contenders: Artists in the running

Florence and the Machine Lungs

Florence Welch fronts the seven-piece band whose music she describes as "like throwing yourself out of a tree". She was brought up in Camberwell, south London. Odds 5/1

Kasabian West Ryder Pauper Lunatic Asylum

A four-piece Indie rock group fronted by Tom Meighan. Originally from Leicester the band is tipped as the heir to Oasis. Odds 5/1

Bat for Lashes Two Suns

Singer Natasha Khan was a nursery school teacher before finding musical fame. She is based in Brighton and is the daughter of a British mother and Pakistani father, spending her childhood in Hertfordshire and Pakistan. Odds 6/1

La Roux La Roux

An electropop duo made up of singer Elly Jackson and composer Ben Langmaid, both from London. The music is heavily influenced by 1980s bands including The Human League and Yazoo. Odds 6/1

Glasvegas Glasvegas

An alternative rock band from Glasgow, described as the best Scottish group for 20 years by Alan McGee, the man who discovered Oasis. Odds 6/1

Speech Debelle Speech Therapy

A South London acoustic rapper. Dropped out of college and at 19 was kicked out of her home to spend three years in hostels. Odds 8/1

Friendly Fires Friendly Fires

The dance-punk band members met at St Albans School. They formed their first group, called First Day Back, aged 14. They reconvened as Friendly Fires after university. Odds 8/11

The Horrors Primary Colours

A garage rock group comprising Faris Badwan, Tom Cowan, who went to Rugby School together, Rhys "Spider" Webb, Joshua Hayward and Joseph Spurgeon. They formed in 2005. Odds 8/1

Lisa Hannigan Sea Sew

An Irish singer-songwriter from Kilcloon in County Meath. She went solo after several years as a vocalist for Damian Rice. Odds 8/1

The Invisible The Invisible

Art rock combo that has been described as the intellectual equivalent of Glasvegas. Odds 10/1

Led Bib Sensible Shoes

Mark Holub, Liran Donin, Toby McLaren, Pete Grogan and Chris Williams describe themselves as a jazz band but have rock influences. They come from London. Odds 10/1

Sweet Billy Pilgrim Twice Born Men

Anthony Bishop, Tim Elsenburg, and Alistair Hamer met while at school in Buckinghamshire. They formed in 2003 to create experimental music which they record in a garden shed. Odds 10/1