The cross-dressing comic and actor said later during a visit to Edinburgh he was “not intimidated” by such behaviour which he described as uncivilised and stated that he used to get people “giving me grief” after he came out as a transgender person decades ago.
Izzard teamed up with Mr Murphy in the centre of Glasgow where protesters, some waving SNP leaflets, attempted to drown them out, branding the Scottish Labour leader a “traitor” and a “warmongerer”.
However, Nicola Sturgeon last night moved to disown the behaviour of the hecklers who she insisted “weren’t acting on behalf of the SNP” as she said people should be allowed to campaign ahead of Thursday’s election without being “abused”.
The scuffles broke out as the protesters disrupted the event, chanting “Red Tories out” at Mr Murphy in clashes reminiscent of those involving the Labour politician during last year’s referendum, when he was pelted by eggs by supporters of independence.
However, Izzard and Mr Murphy hit back at the hecklers.
The comic, who was wearing a dark skirt suit with a red rosette, said: “It’s OK having different opinions, but everyone should be able to put their opinion forward.
“This aggressive, this violent emotion, why violence? Don’t have violence, we should just put our point of view forward and then everyone makes their choice on Thursday.
“This is democracy, it’s all about voting. They should let the democratic process happen, it’s called democracy; we’re putting forward a point of view, we’re asking people to vote Labour and they’re scared of these words being heard.
“Why are they scared of that? Let everyone have their say. It’s called democracy.”
Izzard told how he had volunteered to come north and campaign with Mr Murphy ahead of running for election in 2020, either as an MP or for Mayor of London.
He said: “The Tories are hoping and praying that people might vote in Scotland for the SNP because then David Cameron will cling on to power.”
The comic later made a visit to Edinburgh where he delivered a short speech to Labour supporters and met voters during a walkabout at the Mound and in Princes Street.
Izzard was not confronted by Nationalist protesters during his visit to the Scottish capital, just hours after the clash in Glasgow.
When asked about the behaviour he was subjected to in Glasgow, he said: “It’s aggressive Nationalism. We don’t know exactly who they are, but it’s aggressive Nationalism and is not part of civilisation.
“If people vote Labour in Scotland then we can get rid of the Tories, but those who were shouting want to stop this message getting out there.
“I will not be intimidated. I came out as transgender 30 years ago and I used to have people giving me grief on the street.”
One of the protesters was veteran campaigner Sean Clerkin, who pursued former Labour leader Iain Gray into a Glasgow sandwich shop during the Holyrood election campaign in 2011. He said he has no formal connection with the SNP.
Liberal Democrat deputy leader Sir Malcolm Bruce said: “This is the ugly side of Nationalism.”
Conservative MSP Alex Johnstone said: “These people are the enemies of democracy, and we need the leaders of whatever cause they are associated with to disown them.”
Ms Sturgeon said: “These people weren’t acting on behalf of the SNP.”