The Commercial Court has ordered Independent TD Mick Wallace to repay more than €19m he owes to ACC Bank.
The order for summary judgment means the bank can now take steps to recover the money.
The court was told the money relates to five loans granted to Mr Wallace's company, M & J Wallace, which is in receivership.
The loans were personally guaranteed by Mr Wallace.
Lawyers for ACC Bank said there had been a good constructive working relationship between the bank and Mr Wallace and his company until late 2010.
At that stage the bank commissioned a report into the financial standing of the company.
The bank said it decided to change strategy as the company had significant revenue and trade debts.
Lawyers for Mr Wallace said they were not objecting to the matter being entered into the commercial division of the High Court.
Senior Counsel James Dwyer said Mr Wallace had no defence to the demand for summary judgment.
Outside court, Mr Wallace said he borrowed the money and could not pay it back and that was his problem.
He said as a public representative he had a large responsibility to uphold the law of the land and that was what he was doing.
How the banks operate in this country, or how they had behaved towards him, was a separate issue, he said.
Asked if he had the money to repay the debt, Mr Wallace said no, he was not in a very good position, but he accepted the judgment of the court.