Lord Fitt, moderate Catholic leader, dies at the age of 79

Tributes were paid from across the political spectrum to the lifetime socialist whose career took him from the backstreets of north Belfast to the House of Lords. He was prominent in the civil rights movement in the 1960s and for almost a decade led the Social Democratic and Labour Party, Northern Ireland's largest nationalist grouping.

The one-time merchant seaman was known as a trenchant critic of the republican movement and the use of violence. But in the end he also became a critic of more moderate Irish nationalism, denouncing his own party.

His opposition to republicanism eventually cost him the west Belfast Westminster seat he had held for many years; in 1983 it was captured by the Sinn Fein president Gerry Adams, who still holds it today.

A former Irish premier, Garret FitzGerald, said: "He was great fun, a really entertaining person to work with, but you never knew what was the next thing he was going to say or do."

The Taoiseach, Bertie Ahern, said: "He was a man who practised the message of moderation and tolerance that he courageously preached. He was often in the front line of the Troubles and he experienced violence at first-hand from both sides."

His long-time political opponent, the Rev Ian Paisley, expressed sadness at the news of his death, saying he was very sorry and extended sincere sympathy to his family.

A Unionist political foe, Lord Kilclooney, described him as a wonderful character, adding: "Some politicians you cannot trust, but with Gerry you could always trust him."