Lindsey Buckingham has described his departure from Fleetwood Mac as "not my doing or my choice".
The band announced in April that they would tour without the musician, who wrote and sang on some of their biggest hits, including Go Your Own Way and Tusk.
Buckingham had been a member since he joined the group in 1974 with his then- girlfriend Stevie Nicks.
During a set at a campaign fundraiser for Democratic congressional candidate Mike Levin in Los Angeles, Buckingham was filmed speaking about his firing.
In the video, which was shared on YouTube and Twitter, he said: "It's been an interesting time on a lot of levels.
"For me, personally, probably some of you know that for the last three months I have sadly taken leave of my band of 43 years, Fleetwood Mac.
"This was not something that was really my doing or my choice.
"I think what you would say is that there were factions within the band that had lost their perspective."
He added: " What that did was to harm – and this is the only thing I'm really sad about, the rest of it becomes an opportunity – it harmed the 43-year legacy that we had worked so hard to build.
"That legacy was really about rising above difficulties in order to fulfil one's higher truth and one's higher destiny."
Buckingham also spoke about a "loss of perspective" in Washington, saying: "The loss of perspective we see now is indeed threatening to harm the legacy that is the United States.
"In the context of that you've got to think of what needs to be done.
"It is not going come from the top down, it is going come from the ground up. This is why we are here.
"And so, I am most honoured and most pleased to have been asked in my own small way to help in that pushback which very, very much needs to happen in order to continue the legacy that we all have come to value."
The group will tour this autumn with Tom Petty And The Heartbreakers' guitarist Mike Campbell and Crowded House frontman Neil Finn.
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