Mr Martin is the bookmakers’ favourite to succeed Taoiseach Brian Cowen, who is under immense pressure from his own backbenchers to quit as party leader before the general election.
The backbenchers have indicated they will support tomorrow’s budget, but want a new leader after that to try to contain the damage in the election, where Fianna Fáil is facing the prospect of huge seat losses.
Mr Martin said he would be “interested” in the position when a vacancy arose.
“There are many people within the party who if the situation arose would be interested in the leadership and I would be one of those,” he told RTÉ Radio.
However, he stressed that he was supporting the Taoiseach in pushing through the budget.
“I’m supporting the Taoiseach in implementing the policies that are before us and that is the position. Anything else isn’t relevant in terms of what the country needs,” he said.
Mr Martin follows Arts Minister Mary Hanafin in expressing a desire to be the next party leader. Finance Minister Brian Lenihan is also thought to be keen on the position, although he has not yet publicly declared so. Mr Lenihan has confirmed, however, his intention to run again in the election, despite his illness.
The key question for backbenchers is whether they can now either persuade Mr Cowen to step down or force him out before the election in order to get a new leader in place.
After another disastrous poll for Fianna Fáil last week, showing the party on just 13% and behind Sinn Féin in popular support, a number of backbenchers called on Mr Cowen to go after the budget.
They included Mr Lenihan’s aunt, Mary O’Rourke, who said Mr Cowen’s wife should tell him “it’s not worth it” and persuade him to step down.
“How can you envisage a general election with a leader at that percentage?” Ms O’Rourke asked.
“I envisage myself in Mary Cowen’s boots... saying: ‘Listen, Brian it’s not worth it.’ And he saying: ‘You’re right.’
“I don’t think within himself can he have any good feeling about the party the way it has all turned out for him,” she said.
But Defence Minister Tony Killeen said yesterday he had “no doubt” that Mr Cowen would lead the party into the election.
Mr Killeen said Fianna Fáil was now “used to difficult polls” due to “difficult decisions” it took throughout the economic crisis.
The Government had put “country ahead of party”, he said, with consequences for Fianna Fáil support.
“Anybody who looks at it in that context won’t be surprised that opinion polls are very difficult,” he said.