By Daniel McConnell, Political Editor in Mayo
Updated 8.30pm: Michael D Higgins has strongly rejected claims he has blocked anyone from being a candidate to be the country's next President.
Speaking in Mayo to announce his decision to stand for a second term, President Higgins rejected criticisms from Senator Gerard Craughwell, who complained the timing of his announcement was done to narrow the field.
“I have not delayed for a single day anybody if they wanted to been seeking a nomination for the past six and a half years,” he said.
“As to the timing, this term ends at midnight on the 10 of November 2018, we are four months from that date. Senator Craughwell's business is his business,” he said.
Speaking in Irish, he made it clear that if elected he will serve for the full seven years, adding this is the reason he is standing.
In 2011, on his election, President Higgins insisted he would be a one-term president, but said he has been encouraged by so many people to consider another run.
"This has been invaluable to me,” he said.
As permitted under the Constitution, he said, when the order for an election is made, “it is my intention to offer myself as an independent candidate.”
Addressing reporters, he said he will approach the race and if successful the post with vigour and energy and said his health is excellent.
“I have given long and careful consideration to this decision. I believe there are good foundations for the further development of the Office of President and that the experience I brought to, and have gained within the role, could be of particular value as we enter a period of great challenge and possibility, at home and abroad,” he added.
This evening, Senator Craughwell has written to all Oireachtas members to seek their support in forcing a contest.
"As you may know, I have been campaigning for the last year to ensure that there is always more than one eligible candidate for any Presidential Election now or in the future.
"I strongly believe that a system which prevents candidates other than the incumbent from securing a nomination and mounting a challenge is profoundly undemocratic," he said.
"It is also inconsistent with the spirit of Bunreacht na hÉireann which states that the President shall be elected by direct vote of the people," he said.
During his 2011 election campaign, Michael D Higgins gave full assurances that he would only serve one term and indeed was highly critical of former President Mary McAleese's decision to seek a second uncontested term in 2004, Mr Craughwell said.
"Now his failure to honour his own word, compounds what is effectively the subversion of the democratic election process in favour of a coronation," he said.