Jane Davidson has proved an impressive education minister and a political heavyweight in the Labour government in Wales.
But she lacks the political X factor needed to succeed Rhodri Morgan when he steps down as First Minister, according to a leading political commentator.
In the latest edition of Agenda, published by the Institute of Welsh Affairs, the Cardiff-based independent think-tank, Lee Waters speculates that a poor performance in next year's Assembly elections may lead to Mr Morgan standing down earlier than the 2009 deadline he has set himself.
Mr Waters, ITV Wales's political correspondent, identifies Ms Davidson, the longest-serving UK minister for education, as a front-runner in any leadership contest.
But he adds: "Though well regarded within the education community, Jane Davidson does not inspire much affection within the Labour party. Educated at Malvern girls college, she jars with many class-conscious members of her own party.
"'We would have serious problems with her' is a comment made by several Welsh Labour MPs, who are uneasy with her passion for devolution."
However, Mr Waters speculates that Ms Davidson has done a deal with environment minister Carwyn Jones, whom he tips as a potential replacement for Mr Morgan alongside enterprise minister Andrew Davies.
But he notes some critics consider Mr Jones lazy. Anna Brychan, director of the National Association of Head Teachers Cymru, said: "Being lazy is certainly not a charge you can level at Ms Davidson. We would applaud her pro-devolution credentials too, particularly on league tables and testing."
Ms Davidson wasJon holiday and the Labour party declined to comment.