Sinn Fein is expected to formally endorse Martin McGuinness as its Irish presidential candidate at a top-level meeting in Dublin.
The former IRA leader-turned politician is then due to take part in a press conference for the first time since his candidature was revealed on Friday.
Sinn Fein stunned Irish political circles by announcing Mr McGuinness, who has become a champion of the peace process, was to be its candidate.
In his first comments since returning to Ireland from a US trade mission on Saturday, the Northern Ireland Deputy First Minister signalled he would be willing to host the Queen if elected to office.
He also said he was ready to tackle questions about the IRA during the campaign. But he said he believed he had played a key role in ending the decades of violence and wanted to look to a new future.
On the prospect of meeting British royalty if he was to become Ireland's figurehead, he said: "If the people of Ireland decided that I should be their president, my responsibilities and duties would be to meet heads of state from all over the world and to do that without exception, and that would be my position."
Opponents have already said his former IRA role could become a roadblock and could spark campaign debates that risked upsetting victims of republican violence. "I hope it does not," he said. "No doubt there will be people within the media, particularly the hostile media, who will attempt to do just that."
Mr McGuinness said the same prospect had faced his party leader Gerry Adams when he moved into politics in the Republic, but it had not prevented him winning a seat in the general election.
Sinn Fein said on Saturday night it had the backing of four Independent TDs to ensure Mr McGuinness could stand in the election. With 17 Sinn Fein Oireachtas members, he needed at least three extra signatures on his nomination paper.
Independents Mary Davis and Sean Gallagher officially became candidates on Monday after each secured the necessary support. They are on course to fight it out with front-runner Michael D Higgins, of Labour, and Fine Gael's Gay Mitchell. Independent senator David Norris used a TV interview to say that he would like to re-enter the race, having previously dropped out.