Wendy Alexander has confirmed she will stand for the leadership of the Scottish Labour party.
Ms Alexander has been regularly tipped as a potential leader since devolution and Jack McConnell's resignation yesterday paved the way for a long awaited promotion.
It is not yet known if Ms Alexander will face a challenger or replicate Gordon Brown's "coronation".
Former health minister Andy Kerr and Margaret Curran have both ruled themselves out but Ms Alexander could face a low-profile challenger from the party's left wing.
The Campaign for Socialism has called an emergency meeting this weekend where it will consider fielding a candidate against the former enterprise minister.
Any challenger will need the support of six MSPs to get on the ballot paper.
Confirming her bid, Ms Alexander agreed with the outgoing Scottish Labour leader that the party needed to reform its efforts to appeal to Scottish voters.
She said: "We can use our time in opposition to reform and reorganise the party in Scotland and find new ideas to reconnect with the people of Scotland.
"It will be a big challenge but it is one I am willing to undertake if I win the backing of the Labour membership."
Ms Alexander admitted the Labour party suffered a "bad defeat" at the hands of the SNP in May and would now face a "big challenge" to regain their appeal to the electorate.
Mr McConnell initially refused to admit the scale of Labour's defeat but yesterday bowed to mounting pressure and resigned with immediate effect.
The outgoing leader has continued to attract controversy, after it was confirmed he will become the British High Commissioner for Malawi after the current commissioner completes his posting in 2009.
Although he plans to remain an MSP, Mr McConnell will also work on an education project with the Clinton Hunter Development Initiative to help children in Malawi and Rwanda.
First minister Alex Salmond paid tribute to Mr McConnell's record, saying he had left Scotland in a better state than when he found it.
He said: "Addressing Scotland's poor public health record and expanding Scotland's horizons abroad will be regarded as substantial achievements."