Tánaiste Leo Varadkar has said there is no "mystery" or "conspiracy" around how the decision was reached that the Foreign Affairs Minister should get a State car and two Garda drivers.
It comes amid controversy that former tánaiste Simon Coveney gets to retain his State car, at the cost of €200,000 per year.
Previously, only the taoiseach, tánaiste and justice minister get this service in government.
It emerged on Wednesday night that former taoiseach Mr Varadkar made a request for a State car for his party colleague, Mr Coveney, while he was still in the role.
Labour leader Alan Kelly asked how Mr Varadkar as taoiseach of the last government, made a request for a state car for a minister in a government that had not yet been formed.
Mr Varadkar told the Dáil that it has long been security protocol that the Foreign Affairs Minister needs Garda transport when going to Northern Ireland.
He said: "There is no mystery and conspiracy here, Deputy, and you can try to exaggerate it.
"There are particular security protocols when it comes to the Minister for Foreign Affairs travelling to Northern Ireland.
"Whenever the minister travels there, that person has to have a Garda car and Garda protection.
"They are then met by the PSNI at the border to be escorted through Northern Ireland.
"That has been security protocol for the past 20 years.
"The Tánaiste is usually also the Foreign Affairs minister so this has not been an issue.
"However It did happen on occasion when the minister for Foreign Affairs was not the Tánaiste and they needed civilian drivers when they were south of the border and then had a Garda car when in Northern Ireland.
"When I knew I was going to be the Tánaiste of this new Government and there was going to be a new Foreign Affairs Minister, I asked the Secretary General to look into the matter and decide what was appropriate.
"That was the beginning and end of my involvement in it."