The Mayo TD Ms Beverley Cooper-Flynn owes her former employers National Irish Bank up to £300,000 following her failed libel action.
NIB has confirmed it is pursuing a claim for expenses incurred when it was forced in a court action last year to reveal to RTE the names of people alleged to have benefited from the CMI financial portfolios.
The claim forms part of the estimated £2 million legal fees owed by the TD. RTE won discovery of the documents in May but was subsequently ordered to pay the costs of the action, which amount to between £200,000 and £300,000.
In turn the High Court awarded overall costs in the case against Ms Cooper-Flynn which means she bears all costs, including the NIB bill which was run up through legal fees and the costs involved in the production of around 10,000 documents.
A spokeswoman for the bank confirmed yesterday it would be seeking the costs from RTE. "We will be pursuing RTE for the costs of the disclosure. It is up to RTE whether they pursue Beverley Cooper-Flynn or not."
Mr Kevin Healy, RTE's Director of Public Affairs, said the station had no further comment to make on the case.
However, sources within the station have indicated it would be left with little choice other than to pursue the costs.
The station will also face the legal bills of the Co Meath farmer Mr James Howard, who was indemnified by RTE.
On Tuesday the TD told the local radio station MWR that she was unable to pay the £2 million.
Ms Cooper-Flynn, when asked if she was surprised NIB had not supported her in her court case, said: "I took the view that the allegations made by RTE were personal against me and that is the basis on which I took the case. I was not representing NIB.
"But in my work with the bank it was never the case that I was doing a solo run. I did my job just like anybody else."
Legal sources point out that it will be some time before the exact figure for expenses in the libel case is known.
Cost accountants for both sides work out the appropriate level of costs. If agreement is not reached between them the matter is referred to the Taxing Master for adjudication.
Ms Cooper-Flynn said she would decide by the end of the week whether she would appeal the case to the Supreme Court.
Seventy-one per cent of respondents to a poll on a Co Mayo-based website believe the Fianna Fail parliamentary party was right to expel Ms Cooper-Flynn.
Almost 3,500 people responded to the poll on the www.Castlebar.ie website.