Former Taoiseach John Bruton says he believes President Michael D Higgins ‘is wrong’ not to attend an event to mark the centenary of the partition of Ireland.
President Higgins has denied his not attending is a snub to Britain’s Queen Elizabeth II.
The President says he declined the invite because the event had become politicised - while he was incorrectly referred to as ‘President of the Republic of Ireland’ rather than the President of Ireland.
The church service is due to take place in Co Armagh on October 21st.
Mr Bruton told Newstalk Breakfast the service is a recognition of the existence of Northern Ireland.
"I think he is wrong not to attend, and I think there is time for him to change his mind.
"Obviously it requires great strength of character to change one’s mind, but I think he should do so.
"This is not celebrating partition, it is simply recognising a fact.
"And it is important to recognise that fact - the fact that Northern Ireland exists and is legitimate - was recognised by the Irish people when they voted in the referendum on the Good Friday Agreement.
"The Good Friday Agreement accepts that it is the present wish of the people of Northern Ireland that they remain in the United Kingdom until that view is changed.
"So in going to this event and recognising that Northern Ireland existed for the last hundred years, the President would simply be recognising something that the Irish people have recognised."