Ministers Eamon O Cuiv and Mary Hanafin last night both put themselves forward as Fianna Fail leadership nominees.
Galway West poll topper O Cuiv, who supported Mr Cowen in the leadership heave last Tuesday, had said then that he would contest the leadership if a vacancy arose.
As a grandson of iconic former Fianna Fail Taoiseach Eamon de Valera, Mr O Cuiv would be a favourite of the conservative and traditional wing of the party.
Speaking last night, Mr O Cuiv said he was putting his name forward because he felt the party should have a choice.
"I believe it is important that there should be a competition for the FF leadership and I think there should be choice for the members of the parliamentary party," he said.
"As someone who has travelled this country north and south, the people of Ireland desire a vision and I'd like to have an opportunity to put that forward, and develop it, and I believe it is through getting the FF leadership that I can deliver," he added.
It is possible that his entry into the race could impinge on the strong rural support for Micheal Martin.
Some FF TDs and senators might see Brian Lenihan and O Cuiv as a dream team, with equal appeal for rural and urban voters.
Minister Mary Hanafin, so far the only other candidate, only entered the race at 8.30pm last night. Her spokespereson refused to make any other comment. However her chances are said to have disimproved substantially after she vacillated during the leadership challenge last Tuesday.
Cork Fianna Fail TD Micheal Martin will contest next Wednesday's election for the leadership of Fianna Fail after Brian Cowen's surprise resignation yesterday.
"It must have been a difficult personal decision for him... I didn't know it was coming. Brian Cowen has put the party first. He has served with distinction as a committed pubic servant and he is an honest man with great integrity," Mr Martin said at his home in Cork, after announcing he would run.
"I would say to members of party and the country that I can lead the party with both energy and vision. A vision for policy and organisational change. I will be putting a very detailed program to the parliamentary party.
"People who voted for Brian Cowen came up to me afterwards and said, 'When the vacancy arises, we will support you.' I have been getting calls from all around the country from deputies and ministers. They are saying, 'We will support you.'"
Mr Martin says the party must focus on job creation and education: "From my time in Enterprise and Education, we must have a clear path to job creation. We must remove the blocks for entrepreneurs. We have the dynamics here; it's about the indigenous sector working with the multinationals. We can create jobs."
The former minister who resigned last Tuesday, after losing the leadership challenge to Brian Cowen, admits that, as it stands, Fianna Fail are trailing Fine Gael and Labour in the polls.
"We are vying with Sinn Fein for third place. Some of our party don't get it. They think that we'll get a bounce. It is changed, changed, changed. We've got to work for it. There is no fire in the belly."
"You will have strong Sinn Fein party and independents who will try and pull down a new government, who will themselves work on public finances and getting the deficit down. So Labour will be under pressure. Suddenly things will get ropey when trying to put into effect the four-year plan. We conceived it, so we're honour bound to support it. It is a reverse Tallaght strategy."
"Senator Eoghan Harris is right on this; we should say to the Irish people, 'We will do right by the country, even in opposition.' People want a clear, specific program. We can get out of this crisis; we will get out of this crisis. There is hope.
"I'm 50. That's young. There is still that hunger in me. I can't fully rationalise it; it is something in your belly. I want to do more. I'd love to get to the opportunity someday to pull all that together."
Dublin South East TD Chris Andrews was the first to declare his support for Mr Martin, swiftly followed by Dublin North Central TD Sean Haughey, Clare TD Timmy Dooley, Cork North West TD Michael Moynihan and former Ceann Comhairle John O'Donoghue, of Kerry South.
Mr Martin's constituency colleague Michael McGrath in Cork South Central reiterated his support as did Limerick East TD and former Defence Minister Willie O'Dea. TDs Michael Mulcahy, Michael Fitzpatrick and Michael Ahern also expressed their support.
Junior ministers Peter Power and Billy Kelleher added their support for Mr Martin as did Ned O'Keeffe, Sean Ardagh and Noel O'Flynn. Mr Ardagh said that it was his preference to see Mary Hanafin become Mr Martin's deputy leader.
Junior minister Conor Lenihan said last night that he was "considering his options" and his running mate in Dublin South West, Charlie O'Connor, also declined to declare his intentions on TV.