THERE was an inevitability about serial protester Sean Clerkin leaving his mark on the UK General Election.

Another certainty was his zealous lack of anything approaching repentance over the heckling of Jim Murphy and comedian Eddie Izzard despite allegations of aggression and intimidation.

As unflattering an image as many believe it paints of political protest in Scotland, Clerkin has stood by his disruption tactics, buoyed by past successes.

As recently as last month Scottish Tory leader Ruth Davidson credited the one-time SNP candidate and former community worker with changing history.

Weeks before the 2011 Scottish Parliament elections and with some polls putting Labour and the SNP neck and neck, Clerkin chased then Labour leader Iain Gray into a sandwich shop.

Then, as now, a Labour leader was the focus of Clerkin and a small crowd's anger at Tory policies, as well as the closure of a day care centre, due partly to the Commonwealth Games.

Unlike yesterday though, Gray did not stand his ground. The episode, according to Ruth Davidson at least, led to a backlash against the Labour leader, producing a wave of support for the SNP, a landslide election victory and the independence referendum. History, in other words.

Within days of being re-elected as First Minister, Alex Salmond's choice of venue for his first public engagement was notable; the Accord Centre in Glasgow, much of the focus of Clerkin's protest against Gray.

It may not have been a thank you but it was certainly an indication Salmond and his inner circle were aware of the potential damage Clerkin and his campaigners could create and the political opportunity they had created.

In his early 50s and living with his parents in Barrhead, one of the few traditional working class neighbourhoods in Jim Murphy's constituency, Clerkin has been a political agitator for well over 15 years.

He achieved local prominence in the early part of the last decade as a campaigner against the transfer of council housing stock to a newly-created giant social landlord, staging sit-its and pickets and disrupting meetings of the fledgling Glasgow Housing Association.

When that war was lost he found another cause and some ranks of disaffected, often elderly home owners facing bills due to works by GHA or others with negative experiences of the landlord. On one occasion Clerkin even staged a hunger strike in protest at GHA repair bills faced by home owners.

He had been, in his own description, an SNP local elections 'paper candidate' in 2003 for Cranhill in Glasgow but left a few years later over housing issues.

With the Accord Centre closure Clerkin found another crusade and group of affected folk willing to hook their wagon to his.

The Gray incident certainly emboldened him, with more recent focuses including the UK Government's welfare reform programme and former health checks agency Atos.

Describing himself as a 'non-aligned' socialist and his protest usually freelance, he built further networks with fringe anarchist or far-left groups and really anyone prepared for 'direct action', sit-ins the favoured tactics.

Since the Referendum campaign and the wave of 'anti-Westminster Establishment' politics, new allies have included maverick elements of the food banks network. He is often in the company of Piers Doughty-Brown a Trotskyist former Communication Workers Union official accused of following and filming Labour's Margaret Curran.

In the past year he has been asked to stay away by police public parks, the Commonwealth Games and even the election campaign such is his reputation for protest and event hijackings. New tactics include monologues posted on Youtube.

Last night he stood by his actions, insisting his heroes are 'old Labour' and claiming those of a similar view and still within the party's ranks as the source of his steady flow information on Mr Murphy's whereabouts.

He said: "I even knew Jim Murphy would be at the Neilston Cattle Show on Saturday. The people who tell me are those who, like me, feel betrayed by the Labour Party. That's where it comes from.

"I don't believe Murphy knows I'm going to be there. You should see his face when I arrive. My heroes are Martin Luther King and the old Labour people. That's what I remain.

"I've been brought up from a very early age to be politically aware. My approach is in the long tradition in this country of heckling and direct protest."