Mr Maguire, a senior partner with employment law and personal injuries specialists Thompsons Solicitors, fought long legal campaigns on behalf of Scots who had contracted asbestos-related illnesses in the course of their work.
Mr Maguire’s family issued a brief statement through the solicitors saying he had died at home on Saturday.
The statement said: “Frank’s wife, Fiona, and their sons, Calum, Matthew, Luke and John would very much like to thank all those who have been concerned in Frank’s care, especially over recent weeks.”
Syd Smith, who along with Mr Maguire, was Thompsons Solicitors joint managing partner said: “Our heartfelt sympathies lie with Fiona, the boys, and Frank’s immediate family.
“Frank combined a razor-sharp intellect with a passionate commitment to fight for justice for victims, particularly those suffering from industrial diseases like asbestos exposure and Hepatitis C.
“His loss will be keenly felt by everyone who knew him, but particularly his colleagues, his fellow campaigners, politicians at Holyrood and Westminster, the legal profession and the trade union movement.”
Last year, Mr Maguire won a significant victory when Lord Emslie rejected a bid by insurers to block a law passed by the Scottish Parliament which confirmed the right to compensation of victims of asbestos-related illness.
In a parallel campaign, Mr Maguire also represented people infected with Hepatitis C from contaminated blood products used by the NHS in the 1970s and 1980s. The setting up in 2008 of the ongoing Penrose Inquiry, chaired by judge Lord Penrose, was, in part, a result of this action. He also represented trade unions in the wake of the 1988 Piper Alpha disaster and, most recently, was instrumental in reforming the law governing damages paid to families suing for wrongful death.
Mr Maguire, the son of a policeman, grew up one of seven children in Castlemilk in the 1960s. He initially intended to join the priesthood and studied theology in Rome, but then transferred to Aberdeen University to study law instead.
In an interview in April he outlined his reasons for the change of calling. “I really had an axe to grind,” he said. “I wanted to act for people from my own background, the workers.” Thereafter, he added, he did his “damndest” to tackle anything in the legal system he perceived as unfair.
Leading the tributes to Mr Maguire was Scottish Labour’s Holyrood leader Iain Gray. He said: “I am deeply sorry to hear about the death of Frank Maguire. Frank was a true champion for the underdog. His tireless campaigns for the victims of Hepatitis C blood contamination and former shipyard workers, their families and others affected by asbestos-related diseases, will live on as a tribute to him.
“As legal adviser to many of the UK’s leading trade unions, Frank’s advice and counsel led to many victories for ordinary men and women seeking compensation from rogue employers. He will be sorely missed.”
Leading QC Paul McBride added: “Frank Maguire was an outstanding lawyer and a man of great integrity and decency who was entirely principled in everything he did. He was very much a supporter, professionally and personally, of the trade union movement, and took a lot of cases for people of whom he didn’t always ask payment.
“He always tried to improve people’s rights up and down the country, especially in a workplace setting. On an individual basis, for many people he will have changed their lives dramatically. He will also have set precedents over the years for the way employers should behave and the way they treat their employees.”
Jim Cloughley, 73, knew Mr Maguire for 13 years. A former shipyard worker who suffered from an asbestos-related disease, he now works as a volunteer with the Clydebank Asbestos Group.
He said: “Frank was a wonderful human being. He was one of the legends of the campaign for changes in the law for asbestos victims.
“The Scottish legal system, led by Frank, has always been ahead of the rest of the UK in changing legislation in favour of victims of asbestos-related diseases, particularly for those victims who, once diagnosed, have a limited life. He will be sadly missed by all of the campaigning groups of Scotland and indeed the Asbestos Forum of England.”
Funeral arrangements will be announced this week.