Former Labor premiers Bob Carr and Morris Iemma have gone to war over who was responsible for the rise of Eddie Obeid amid warnings that corruption hearings involving the notorious powerbroker will have dire consequences for the party at the federal election.

Senator Carr, now the Foreign Affairs Minister, has accused Mr Iemma, his successor as premier, of a serious error by allowing Mr Obeid ''special status'' in his government.

Clash: Morris Iemma, left, and Bob Carr. Credit:James Alcock, Dominic Lorrimer

''I'm sure that Morris Iemma, a very decent - decent and honest figure - would reflect that it was a cardinal mistake to allow Obeid that special status and privilege,'' Senator Carr says in comments that will go to air on Monday night on the ABC program Four Corners.

''And people who then ran the state ALP machine were making a terrible mistake to confer some special status on him. For what reason? What could he deliver? What qualities could he bring?''