Ian Paisley, 85, perhaps the most controversial politician ever to come out of Northern Ireland, is seriously ill in a hospital in Belfast, having been admitted over the weekend complaining of heart problems.

An array of Ulster lawmakers, including Stormont First Minister and Democratic Unionist leader Peter Robinson and Sinn Fein Deputy First Minister Martin McGuinness, have expressed their admiration for the firebrand Protestant minister and maintained vigil at his bedside at the Ulster Hospital, Dundonald, just east of Belfast.

A spokesman for Robinson and McGuinness said in a statement: The First Minister and the deputy First Minister have both been in contact with the Paisley family. They have offered their best wishes to Dr Paisley and his family and call on the community to give prayerful support to Ian and his family at this time. The First Minister and the deputy First Minister would appeal for the Paisley family to be given the space and privacy they deserve and that their wishes are respected.

The Reverend Roy Patton told the Belfast Telegraph newspaper: We have had our differences in the past but it would be inappropriate to dwell on those differences at the present time but rather recognize the qualities that Dr. Paisley has brought to his ministry, his faith, his pastoral word and his desire to serve in the ways in which we all seek to serve.”

Patton added: We want to convey to Dr. Paisley and to Baroness Paisley and to the family our support and our prayers.

Paisley, the very symbol of Protestant Northern Ireland and a strong supporter of the Union with Great Britain, formed the Free Presbyterian Church in 1951 after breaking off the main Presbyterian Church. He served as an MP for North Antrim for nearly four decades.

Once a vociferous opponent Irish Nationalists, he was nonetheless elected First Minister in 2007 with McGuinness, a former leader of Irish Republican Army (IRA) in Londonderry, as his deputy First Minister.

Paisley and McGuinness, once bitter enemies, became the best of friends. It was an astonishing political and personal evolution.

After serving as a preacher for 65 years, Paisley delivered his final sermon in late January.

Decades ago, Paisley railed against the Catholics and even denounced Pope John Paul II as the anti-Christ. He was also a bitter opponent of homosexuality and actively sought to re-criminalize the practice.