Charles Kennedy, a man who has been remembered as being one of the most principled members of British politics, made an iconic speech at an anti-Iraq war demonstration attended by thousands in Hyde Park in 2003.
Mr Kennedy, who was then the leader of the Liberal Democrats, spoke out against the British and American governments, and questioned the legitimacy of their reasons for going to war.
Mr Kennedy passed away at his home in Fort William on Monday at the age of 55.
The Scottish ex-MP's death was not believed to be suspicious and the cause of death has yet to be confirmed.
Tributes have flooded in from family, friends and colleagues, with many calling him a man of "courage", "principle" and "decency".
On February 15, 2003, Mr Kennedy made a rousing speech to thousands of demonstrators in Hyde Park against the "deeply worrying" reasons for going ahead with the Iraq war and he became one of the most senior Westminster politicians against the conflict.
Mr Kennedy told demonstrators that the United Kingdom should work with the United Nations (UN) and put their faith in the weapons inspectors.
The full transcript of Mr Kennedy's speech is below.
"Ladies and gentleman I am delighted and privileged to join with you here this afternoon on what is without doubt is this historic occasion. And given the events at the United Nations in New York yesterday when they spoke, today across the world the people are speaking and the Prime Minister and the President have got to start listening. That is our message to them.
"For months now I have been asking questions in the House of Commons of the Prime Minister and I have not been getting the answers.
"What's come back has been confusing, alarming and you are all here because like me you think it lacks persuasion. So it is no wonder that so much of British and European opinion is not convinced but neither is a lot of American opinion convinced either and that is all too often overlooked in the reporting that we see.
"Now my party has consistently argued from the outset for four principles. First, the mandate of the United Nations must be the one that takes the decision and gives the legitimacy. And secondly that those decisions have got to be based on adequate information. That means full compliance with the weapons inspectors.
"So I have joined you here today and I have been asking these questions for months in Parliament because I am not persuaded by the case for war. The arguments have been contradictory and inconsistent and the information has all too often been misleading as well as inconclusive.
"It's no wonder that people are scared and confused. I say this to you quite seriously as somebody who personally happens not to be a pacifist but has the utter respect for anyone for grounds of conscience who is.
"As somebody who is not actually anti American but is deeply worried by this Bush administration. And as someone who is under no illusions about the brutal dictatorship and the appalling regime which is Saddam Hussein.
"But I conclude by returning to the United Nations. If the great powers of the world ignore it then great damage will be done to the world order and the best hope of international justice for everybody in the world.
"And without a second United Nations resolution based on authoritative fact from the weapons inspectorate I can assure you there is no way in all conscience that the Liberal Democrats either could or should support a war and we will not.
"International justice also requires a serious restarting of the middle east peace process. I wish the United Nations was able to devote its time and energies to that constructive process rather than the destructive process that we are seeing underway at the moment.
"That absence of a middle east process can only fuel extremism and international terrorism. This is the riskiest moment for Britain since Suez.
"Our country has a principled and a responsible role to play on the world stage but to do so we have to pursue international justice through the United Nations and our government has got to take its people with them. It's patently failing and that is my message for you today. Thank you."
Twitter users have shared their fond memories of Mr Kennedy's keynote speech, with many applauding him for the courage and integrity his showed by speaking out against the war.
So sad Charles Kennedy. His finest hour most definitely on stage in Hyde park speaking against the impending Iraq invasion.— christian martin (@CAdamMartin) June 2, 2015
I remember seeing Charles Kennedy march into Hyde Park in 2003. He didn't just say he was against the war – he stood with us. Be at peace.— Pip (@pipsterish) June 2, 2015