Tributes have been paid to former trade union leader Lord Scanlon who has died at the age of 90.

The ex-engineering workers union boss passed away in his sleep on Tuesday following a heavyweight career in the Labour movement.

As Hugh Scanlon he led the Amalgamated Union of Engineering Workers (now the AEEU wing of Amicus) during the peak years of union power in the 1960s and 70s.

Tony Blair led the tributes to his party colleague.

"Hugh was one of the towering figures of the Labour movement in the 1970s and a formidable champion of the interests of his members and all working people," the prime minister said.

"His tremendous contribution will be remembered by an entire generation of our movement and he will be sadly missed."

Amicus joint general secretary Derek Simpson said his predecessor was a "giant".

"We receive the news with great sadness. The movement has lost one of its past giants," he said.

And TUC general secretary Brendan Barber concurred.

"Hugh Scanlon was a giant among trade union leaders," he said.

"His heart was always with the left, yet he was a pragmatic leader who always sought the best for his members and to sustain a Labour government."