Ms Curran says Mr Gray would give the party a fresh start
The defeated Labour candidate in the Glasgow East by-election has given her backing to Iain Gray as the party's new leader in the Scottish Parliament.
Margaret Curran MSP had been tipped as a potential candidate in the race to succeed Wendy Alexander as leader.
But her defeat at the hands of the SNP in the by-election effectively ruled her out of the contest.
Ms Curran said she believed Mr Gray could offer "a new voice and a fresh start" for the party.
She added: "I think that Iain has a deep commitment to the Labour Party and one which will see us through many of the tests and challenges that the future years will undoubtedly bring.
"I do think that the time is right now for a new voice and a fresh start and I do believe that the best person for the job is Iain Gray."
Mr Gray is one of three candidates to have confirmed they will be standing in the leadership ballot, alongside former deputy leader Cathy Jamieson and former health minister Andy Kerr.
Candidates need to be nominated by at least five other MSPs to be eligible for the contest, with the nomination process ending on Friday.
Labour has published details of the nominations online, which shows that Ms Jamieson already has the support of 10 members to stand in the contest - three more than former enterprise minister Mr Gray.
Among her backers are former ministers Malcolm Chisholm, Patricia Ferguson and Hugh Henry, her campaign chief.
Senior backbench Labour peer Lord Foulkes, the Lothians MSP, and former communities minister Rhona Brankin are backing Mr Gray.
The party has yet to receive any nominations for Mr Kerr or other possible contenders Cathcart MSP Charlie Gordon and East Renfrewshire MSP Ken Macintosh.
The election has come about after Wendy Alexander quit last month in a row over donations to her leadership campaign last year.