Former clamper Joe Carrick is a key figure in the Luas dispute.

Mr Carrick, whose email address starts with 'EireFreeJoe', is a long-serving driver and one of four shop stewards representing his colleagues. He makes regular appearances on the picket line at the Red Cow Depot in 'Union TV' broadcasts that are available on YouTube and have been posted during the dispute.

Sources said he has "flirted" with various militant left-wing groups.

A description of one YouTube broadcast notes that the drivers are getting support from local politicians including Bríd Smith of People before Profit and Paul Murphy of the Socialist Party.

On Easter Sunday, when the shop stewards refused to back down from striking during the 1916 centenary commemorations, Mr Carrick said that the reasons for the strike go beyond the Luas dispute. "We're here picketing today 100 years after the 1916 Rising because we firmly believe in what we're fighting for," he said.

"We're not only fighting for ourselves but we're fighting for all working class people in Ireland," he continued.

Along with his driver colleague Richard McCarthy, another shop steward, the two men have been listed in the past as 'sponsors' of an event for union activists who are strongly anti-privatisation and anti-mainstream union.

Literature for the event, 'Reclaim the Unions', said it was a forum for trade union members who want to set up a network of shop stewards and activists to develop an effective opposition to the "pro-partnership union leaders".

It said such a network could mobilise support for "fighting action" to defend jobs, pay, public services and to "defeat privati-sation".

The group aims to fight privatisation of semi-State companies, and said it had led to massive job cuts and attacks on pay and conditions at Eircom and Aer Lingus.

It said its aims could only be achieved if ordinary activists organise to give solidarity and support to fellow workers and to democratically take "our unions back from 'leaders' who have shown that they are unable and unwilling to defend our interests".

"Time and again our so-called union leaders have told workers that they have to accept these attacks," it said in a promotional document.

"We need a trade union movement capable of fighting for its members and answering the cutback consensus of the bosses, Government and the EU/IMF."

Although they were part of the negotiating team that brokered a deal for Luas staff at the Workplace Relations Commission that was recommended in a ballot by Siptu, the shop stewards were highly critical of it afterwards. In particular, they objected to clauses that meant they would have to work nine-and-a-half hours a day and accept entry pay rates that are 10pc lower for new recruits up to their fourth year.

Sources said they have used similar tactics to the persuasive union leaders like Brendan Ogle in the past, by presenting a united front and encouraging their Luas colleagues to hold out for a better offer. Carrick has described "hysteria in the media" surrounding the drivers' first claim for pay rises of up to 54pc for those at the top of the payscale - which would see their wages rise from €42,247 to €64,993 by January next year - as a "naked attempt" to keep their pay and conditions down.

He also said management's strategy was to "directly copy and paste out of the Maggie Thatcher memoirs - force a strike and see if they can outlast the union".

Irish Independent