Grand Rapids, Michigan: Former US presidential contender John Edwards has backed Barack Obama to be the next Democratic candidate.

Edwards, who dropped out of the race to be the democratic White House candidate, appeared on stage with Obama in Michigan and said "The Democratic voters in America have made their choice and so have I."

The move will boost the Obama campaign, who is now the clear favourite to win the nomination.

Rival candidate Hillary Clinton, who has vowed to stay in the race after a big win in the West Virginia primary on Wednesday, dismissed the news.

Campaign chairman Terry McAuliffe said: “We respect John Edwards, but as the voters of West Virginia showed last night, this thing is far from over."