A group of around 20 demonstrators, drawn from different fringe groups, disrupted a street rally held by Jim Murphy and comedian and Labour supporter Eddie Izzard.

They jostled Labour activists and yelled abuse in their faces, as they played loud music from a sound system to drown out the speeches.

A girl aged about six or seven was carried from the crowd in tears.

The melee threatened to become a running battle as Mr Murphy tried to lead his supporters from outside St Enoch subway station to a spot 50m away.

A number of people, including STV reporter Carole Erskine, were pushed to the ground in the confusion.

Mr Murphy and Mr Izzard attempted to make speeches urging Scots to vote Labour to keep the Tories out but were cut off.

Among the protestors was Sean Clerkin, a former SNP candidate who has tried to disrupt a string of Labour events during the election campaign, including a rally on Friday at which Ed Miliband spoke.

He claimed to have been assaulted as they blocked his path towards the Scottish Labour leader.

Wearing a red Yes campaign badge, he used a megaphone to scream in the faces of Labour activists as they attempted to protect Mr Murphy.

Other protestors shouted "Red Tory scum" at the Labour group, which was made up of about 30 people.

Bank Holiday shoppers looked on horrified.

The "action," as protestors called it, was organised by anti-austerity campaigner Piers Doughty Brown and James Scott, the leader of a fringe nationalist grouping called Scottish Resistance.

Mr Scott said: "We are not provoking them, we are annoying them."

Izzard 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.''

The comedian added: "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.''

Mr Murphy said: "This sort of aggressive nationalism should have no place in our election.

He added: "This isn't the type of Scotland we want, Scotland, the Labour Party and the people of Scotland are much better than this sort of aggressive nationalism.

"On Thursday we'll stand up to this anti-democratic street nationalism, and get David Cameron out of office with a vote for the Labour Party.''

Clerkin and Doughty-Brown were among a group who also heckled and abused people going to a Labour rally in Glasgow on Friday night.

Politicians and party memebrs were heckled and met with chants of "red Tories out" as they gathered at Tollcross Leisure Centre where Ed Miliband was making a speech.

Cars believes to be carrying Mr Miliband were chased through the car park.

Councillors including Frank McAveety and Bill Butler were met with abuse as they entered. Some shouted "scum" close up to people's faces as they walked past. Mr Clerkin entered the building and was escorted back out by police officers.

The centre was still open to the public and one young girl was seen in tears with her mum as they walked through the protest.

Last month, it emerged Police Scotland had asked Mr Clerkin to reveal his plans for challenging Jim Murphy in a meeting called specifically to discuss direct action against the Scottish Labour leader.

The officers did not ask Clerkin to stop protesting, but said it would help "public safety" if he shared his plans in advance to avoid a police call-out and possible arrest.

Police Scotland also last month it would be stepping up protection of Mr Murphy due to protesters repeatedly attempting to gain access to Scottish Labour campaign events.

Officers had previously been called to the Royal Concert Hall in Glasgow after serial protester Mr Clerkin turned up and attempted to gain entry to an event attended by Ed Balls and Mr Murphy.

In an interview with sister paper the Sunday Herald in April Scottish Conservative leader Ruth Davidson said Mr Clerkin had changed history after chasing the then Labour leader Iain Gray into a sandwich shop in the last Holyrood election.

Ms Davidson said the episode led to a backlash against Mr Gray and produced a wave of support for the SNP.

Speaking afterwards, Mr Clerkin stood by his approach, denying it was intimidating and aggressive whilst handing his opponents an open goal.

He insisted he was not acting on political instruction, saying he had left the SNP eight years ago in a protest over its housing policy.

The serial campaigner also claimed he had been tipped off about the event by disaffected members of the Labour Party within Mr Murphy's East Renfrewshire heartland

He said: "Of course (his protest) is a good thing. This isn't just me. There were 25 other working-class people there, people who are saying Labour has become the red Tories and we're there to demonstrate against £30billion in cuts.

"This will be portrayed as something else by the establishment but its just old-fashioned political heckling, a democratic tradition. But I am being called obsessive and delusional."

He added: "I was told by members of the Labour Party in East Renfrewshire at 8.30 am this morning. I had time to ring around people. I believe the intentions of those who told me was honourable. They have told me plenty in the past."

Additional reporting by Gerry Braiden and Magnus Gardham.