Published Monday, 06 February 2012
The Rev. Ian Paisley speaks to press outside the house of commons in March 2010 (© Getty)
UTV understands that the 85-year-old Rev Paisley is being treated in the intensive care unit in the hospital in east Belfast, after suffering from heart problems on Sunday.
In a statement on Monday afternoon Ian Paisley's wife, Baroness Paisley, confirmed her husband, former First Minister Lord Bannside, is currently being treated in the Ulster Hospital.
She requested that "the family's privacy be respected at this difficult time".
In December Rev Paisley preached his final sermon after standing down as moderator of the Free Presbyterian Church.
In an interview with UTV at the time, he said of his ministry: "I would say the average of a man that has good health should do about 25-30 years, but I have doubled that so I have done very well!"
Asked whether he felt his mantle as a politician or a churchman has been the most important, Rev Paisley said he wished to be remembered as a "gospel man".
He said: "Oh by long and far the gospel man. Really the fact that I was in politics came as a result of the faith that I preached."
After retiring from both church and political life, he planned to write his autobiography.
In his heyday, Rev Paisley was a fierce opponent of sharing government powers with nationalists and republicans in Northern Ireland.
However, he was elected First Minister in May 2007 with Sinn Féin's Martin McGuinness as Deputy First Minister.
The two men went on to develop a remarkable friendship - both on a personal and professional level - which earned them the nickname the "Chuckle Brothers".
© UTV News