The Conservatives have unveiled their candidate to fight the Ealing Southall by-election on 19 July.
Mr Cameron hailed Mr Lit as an 'outstanding candidate'
Businessman Tony Lit has spent the past 10 years running local radio station Sunrise and is involved in regeneration projects in the area.
The by-election was triggered by the death of Britain's oldest MP Piara Khabra, who was 82.
A by-election will be held in Sedgefield on the same day triggered by the retirement of Tony Blair.
During a visit to the constituency, Mr Cameron said Mr Lit was an "outstanding" candidate.
Mr Lit, who is also director of the Asian Lifestyle Show and the not-for-profit regeneration body Heathrow City Partnership, said: "Under David Cameron's leadership this is a party that recognises people from all backgrounds."