Sitting MEP Matt Carthy has confirmed that he is seeking to contest this May's European Elections.
As the Sinn Féin MEP for the Midlands-North West constituency has already been selected to run for the Dáil in the Cavan/Monaghan constituency, he was not expected to contest the European Elections.
In a statement he said he will be seeking his party's nomination at the selection convention in Cavan on Sunday 3 February.
His statement said: "The May elections could be the most important EU contests ever for our country.
"Brexit will continue to dominate. With the potential loss of northern representation in parliament it is vital that we send representatives from an all-Ireland party, a party that has a proven track record of inserting Irish concerns into the heart of the Brexit process, we need representatives that won't be beholden to either the Brussels establishment or the Irish government.
"In essence we need MEPs who will fight for Ireland. That has been my role and I wish to continue that work in the new term."
Mr Carthy was first elected to Carrickmacross Town Council as a 21-year-old in 1999 and he served on Monaghan County Council from 2004 until 2014.
He won the third of four seats in the Midlands North West constituency in the 2014 European elections with an 18% share of the vote.