Fine Gael TD Mr Michael Ring faces a legal bill of about €60,000 following the failure of his High Court constitutional challenge to legislation abolishing the "dual mandate".
Yesterday, Mr Donal O'Donnell SC, for the State, said he was instructed not to press for his side's costs in the matter but he was also directed to resist any application for the State to pay Mr Ring's costs.
Last week, when rejecting Mr Ring's challenge, Miss Justice Laffoy said the TD had to choose between his desire to be a member of the Dáil and his desire to remain a member of Mayo County Council.
Mr Ring had argued that he had a constitutional right to stand for election to the county council. However, the judge held that the right of a citizen to stand for election to a local authority was not constitutionally guaranteed.
Mr Ring had challenged provisions of the Local Government (No 2) Act, 2003, which had the effect of disqualifying persons who are members of either House of the Oireachtas from being elected or co-opted to, or from being a member of a local authority.
Miss Justice Laffoy, in upholding the 2003 Act, said the powers and functions of local authorities, including those eligible to be members of such authorities, were matters for the Oireachtas.
Yesterday, Mr Gerard Hogan SC, for Mr Ring, asked for two of the four days costs of the hearing. He argued the issue before the court was of profound constitutional importance as it concerned the relationships between national and local government.
Mr O'Donnell said the State was strongly opposing Mr Ring's application. There was nothing which could be described as reprehensible in the way Mr Ring had been treated, he added.
Ms Justice Laffoy said she did not think the case came within the truly exceptional category of cases in which unsuccessful plaintiffs may secure costs.
If she were to allow costs, it might be viewed as giving a free run in cases involving new legislation or new constitutional provisions, the judge said. She said she would make no order as to costs.
The effect of the judge's decision is that Mr Ring will have to pay his own side's costs, estimated at some €60,000.