Mattie McGrath says he will vote against the IMF-European loan agreement when it goes before the Dáil next week.
The Tipperary South TD is set to remain outside the Fianna Fáil Parliamentary Party after voting against legislation to slash the national minimum wage.
He says he was "double-crossed" by the Finance Minister who reneged on a promise to impose a tax on bonuses being paid out to staff at AIB.
Mr McGrath says he negotiated the tax with Brian Lenihan minutes before a vote on the Social Welfare Bill last night, only for it to be reneged on minutes later.
“We actually discussed the rate," said Mr McGrath. “He said 70% tax, and I said: “No, I want it 99”, and he said 80, and I said: “No, 90%”.
“I wish him well, health-wise and everything else, we’re very good friends, but I told him this morning that I was double-crossed as far as I was concerned, and I don’t like that.”
“That’s not my style of politics.”