text: The election will take place at the SDLP's annual conference in November.
  Mr Eastwood said his party has had poor election results, was lacking in ideas and he wanted to take it in a fresh direction.
  The 32-year-old, who is the SDLP's youngest MLA, said an Irish nationalist party cannot be led from Westminster.
  He said Dr McDonnell has "given his life to the SDLP " and would continue to be South Belfast MP.
  Mr Eastwood has been nominated by nine party branches to challenge the SDLP leader.
  He said his challenge "was not personal " and said politics needed "a new generation".
  Mr Eastwood is a former Mayor of Derry and in 2012, he faced controversy after carrying the coffin of a friend who was a former member of the Official IRA and the INLA.
  He told the BBC: "Seamus Coyle was a friend of mine and I carried the coffin out of respect."
  He said Mr Coyle was on his "own peace process journey".
  Mr Eastwood, who has been in the party since he was 14, said the SDLP should "stand for a positive brand of progressive nationalism".
  Dr McDonnell has led the SDLP since November 2011
  Last week, he told the BBC he did not expect a leadership challenge.
  "I don't expect to face a challenge, but if there's a challenge, I'll face it," he said.
  Dr McDonnell has faced calls to stand down as leader from a number of party grandees including Brid Rodgers and Seamus Mallon.
  The Foyle MP, Mark Durkan, used an interview on the BBC The View programme to call on the South Belfast MP to step aside as leader, arguing that the party leader needs to be at Stormont.
target: The Social Democratic and Labour Party (SDLP) MLA Colum Eastwood has confirmed that he is set to challenge Alasdair McDonnell's leadership of the party.