Minister for Social Protection Regina Doherty has been told she has to pay back an allowance she received in her former role as Government chief whip following a report by the Attorney General.
Controversy over a supplementary payment of €15,829 arose after Taoiseach Leo Varadkar appointed a record four Ministers of State to the role of so-called super junior Minister.
This allows them to sit at the Cabinet table without any vote in Government decisions, but legislation allows for only two super junior Ministers to be paid the allowance.
In the previous cabinet, minister of State at the Department of Health Finian McGrath and minister of State at the Department of Defence Paul Kehoe received the additional €15,829, as did Ms Doherty.
Ms Doherty told The Irish Times she had received a letter from the Department of Public Expenditure and Reform "telling me they made a mistake".
She said she had made an arrangement to have the money taken out of her salary until it was paid back.
Ms Doherty had previously said she would pay back any money she received as Government chief whip if asked to do so.
The Attorney General’s review also examined whether current Government chief whip Joe McHugh and Minister of State for Higher Education Mary Mitchell O’Connor should receive the money.
The Attorney General ruled they should not. However, the pair had not started receiving the allowance.
Labour leader Brendan Howlin first raised concerns about the matter when he described the payment to Ms Doherty as unlawful.
Speaking in the Dáil in June, he said the allowance was being paid on the understanding that it was for her responsibilities as Fine Gael whip.
But he said the law was “crystal clear” and “no allowance can be paid to a party whip if the person is a Minister or Minister of State”.