One of the giants of British politics has passed away after Lord Menzies Campbell, former leader of the Liberal Democrats, has died at the age of 84. Party leader Sir Ed Davey described Lord Campbell – known as Ming – as “a dedicated public servant, a tireless champion for Fife, St Andrews and the UK, and a true Liberal giant”.

The former MP for North East Fife died in London after a period of respite care. He was Lib Dem leader in 2006-7, and previously was the party’s foreign affairs spokesman. During the 2003 invasion of Iraq and its bloody aftermath, he was one of the most eloquent and effective critics of Tony Blair’s decision to join the American-led coalition to oust Saddam Hussein. His performance, in partnership with the party’s charismatic leader Charles Kennedy, helped propel them to the best general election result of any Liberal party since the days of David Lloyd George.

Sir Ed said: “With a parliamentary career spanning five decades, Ming Campbell was a dedicated public servant, a tireless champion for Fife, St Andrews and the UK, and a true Liberal giant. He was the Liberal Democrat spokesperson on foreign affairs when the world changed on 9/11, and his principled leadership opposing the Iraq War was a mark of his morality, courage and wisdom. He spoke up for what was right, even when it was hard.

“Like so many of us, I benefited greatly from Ming’s advice and guidance over the many years we worked closely together. But more than that, he was an incredibly warm and caring friend and colleague, with such generosity and humour.

“Ming was always great company – whether talking about sport with the authority of a captain of Britain’s athletics team and a British 100m record-holder, or asking about you and your family, when he would always pass on kind thoughts from his wife, Elspeth – his rock.

“All of us in the Liberal Democrat family and beyond will miss him terribly. Our thoughts are with all who loved him.”

When Menzies Campbell was elected Liberal Democrat leader at the age of 64, his redoubtable wife Elspeth was heard bewailing “What are we doing? We should be retiring and sitting in front of the telly.”

It was an all-too-prescient remark: just 19 months later he was indeed “retired”, forced to resign after proving unable to shake off claims he was too old for the job.

It was an ignominious end for a politician who for more than a decade as his party’s foreign affairs spokesman had established himself as one of the most authoritative voices at Westminster, respected across the political spectrum.

While he was significantly older than his Labour and Conservative rivals when he became leader – the Tories’ David Cameron was just 39 – it was not just age which told against him.

With his upright, patrician air and immaculately tailored suits, he could appear like a figure from an earlier era, uncomfortable with the demands of the 24-hour news cycle for instant soundbites.

Having made his name in the rarefied field of foreign affairs, he struggled with the bearpit of Prime Minister’s Questions: his first attempt to take on Mr Blair was a fiasco from which he never truly recovered.

Despite his frustration at the incessant focus on his age – not helped by the “careless talk” of some other senior Lib Dems – he nevertheless accepted his ousting with characteristic good grace.

But then, for all his gravitas and clear sense of duty, he was in some ways an unlikely politician.

He once admitted his “real obsession” was sport: as a young man he was a top class sprinter, holding the British 100m record for seven years and competing in the 1964 Tokyo Olympics.

After athletics gave way to the law and a career as a barrister, he said his real ambition was to become a judge, describing himself as “a lawyer first, politician second”.