The Seanad Committee on Procedure and Privileges has decided that it cannot intervene in the row involving the nomination of Fianna Fáil's Marc MacSharry to the Banking enquiry.
The Sligo-based Senator was voted onto the inquiry last week, putting the Government in a minority on the body.
The committee also decided that it could not entertain any complaint about any possible conflict of interest involving Senator MacSharry until the terms of reference of the inquiry were agreed.
Last week the government objected to Senator MacSharry, with its leader in the Seanad citing a conflict of interest, a claim Maurice Cummins later withdrew.
Yesterday Taoiseach Enda Kenny said the Government had to have a majority on the inquiry before terms of reference could be agreed.
There is speculation that the Government may add two members to the inquiry to insure it has a majority.
Labour's nominee Susan O'Keeffe was absent from the crucial selection committee meeting last week, allowing Fianna Fáil to vote Senator MacSharry on to the inquiry.
The issue was discussed at this evening's meeting of the Labour Parliamentary Party.