London--Labour MP Chuka Umunna has said he is running to become Labour leader.
He made the announcement by posting a video on Facebook as he met activists in Swindon.
The Streatham MP and shadow business secretary is the second candidate to formally declare in the race to succeed Ed Miliband, who quit last week.
He said he had spoken to around 40 Labour candidates who lost out to Conservatives in target seats at the election before deciding to stand.
Liz Kendall has already thrown her hat into the ring to become opposition leader while Yvette Cooper, Andy Burnham and Tristram Hunt are all seen as potential candidates.
On Facebook, Mr Umunna said Labour should be winning all over the country and rejected suggestions that it could take a decade for the party to get back into power.
"I think we can and should be winning in seats like Swindon," he said. "North, south, east, west - we can absolutely do it as a party."
Mr Umunna has suggested Labour failed to fully reach out to middle-income voters during the election campaign, a criticism echoed by senior figures on the right of the party including Alistair Darling and Lord Mandelson.
The unmarried 36-year-old Streatham MP entered Parliament in 2010 after a career as a solicitor for a city law firm.
The son of a Nigerian businessman, who settled in the UK, he was privately educated at St Dunstan's College, in South London, and studied law at Manchester University.
His father Bennett returned to Nigeria to embark on a political career, as an anti-corruption crusader, but died in a road accident in 1992.
In an interview with the BBC's Iain Watson, Mr Umunna said Labour had to become the party of "aspiration" again and to persuade people it will back the "wealth creators" and those who "make the effort".
BBC
