Spending by the President's office will be scrutinised by the Oireachtas' most powerful committee today.

The Public Accounts Committee is examining the issue, despite objections from senior politicians.

Critics of this hearing have said it is ill-timed and a blatant attempt to politicise the PAC and undermine Michael D Higgins.

The Government's chief civil servant Martin Fraser, who will appear at the committee, went as far as to question whether it was even constitutional.

Both the Taoiseach Leo Varadkar and the Fianna Fáil leader Micheál Martin have questioned the timing of the hearing - as it comes just a day before nominations close in the Presidential campaign.

The spending of the office of the President usually comes in at around €3m a year.

However no breakdown is given, and the office of the President is exempt from Freedom of Information law - meaning we do not have a clear picture of how money is spent.