The Rev Ian Paisley is in intensive care after suffering acute cardiac problems.

The former Northern Ireland First Minister was admitted to the Ulster Hospital in Dundonald on the eastern outskirts of Belfast.

A statement on behalf of his wife, Baroness Paisley, said: "She requests that the family's privacy be respected at this difficult time."

Mr Paisley, 85, was rushed to hospital on Sunday, 10 days after preaching his final sermon as a minister. He is a former moderator and founding member of the Free Presbyterian Church and was MP for North Antrim for almost 40 years.

Mr Paisley, now known as Lord Bannside, was succeeded in North Antrim by his son Ian Jnr.

Party colleagues were briefed in a meeting at Parliament Buildings, Stormont, and prayers were said. One member said they were given no details about how he became ill or his condition. "We were just told he was unwell and in hospital. That was all."

It is understood Mr Paisley has been on medication for several years for an enlarged heart, possibly since 2004. According to one source tonight the illness could be linked to heart failure, not a heart attack. There had been concerns several years ago about Mr Paisley's health when he lost weight and looked gaunt.

But he made a good recovery from heart problems and while his voice was showing signs of obvious weakness, some people who were at his farewell sermon at the Martyrs Memorial Church in Belfast on January 27 remarked on how well he appeared for his age.

After withdrawing from church and public life he was planning to write his autobiography.

Mr Paisley's five children - twin sons Ian Jnr and Kyle, an ordained minister as well, and three daughters, Rhonda, Sharon and Cherith - were among the 3,000 people for his final address.