The industrial dispute involving butchers at Superquinn appeared to be esclating last night after SIPTU announced it would seek an all- out picket, which could draw other unions into the dispute.
The 103 butchers called a strike on Monday after talks linking an 8 per cent pay rise to increased work flexibility ended in impasse.
The company, which has placed its 5,300 workforce under protective notice, accused SIPTU of failing to abide by recommendations of the Labour Relations Commission and Labour Court.
As butchers picketed Superquinn stores in Dublin and Naas, Co Kildare, yesterday, many general floor staff, who are members of the Mandate union, refused to cross picket lines.
SIPTU said it wanted to bring the dispute to a head by applying to the Irish Congress of Trade Unions for a strike ballot of all workers.
However, a spokeswoman for the chain last night dismissed claims by union leaders that 5,000 staff refused to cross picket lines yesterday. She said only 400 had stayed away from work.
Superquinn management recognise that butchers are entitled to a pay rise but say this could only be achieved if they agreed to greater flexibility.
Management said butchers rejected an €800 interim lump sum pending resolution. The spokeswoman said it was standard practice in industrial disputes of this nature to place staff under protective notice.
The chain's executive chairman, Mr Fergal Quinn, apologised to customers for the inconvenience caused by the strike. He said Superquinn remained available for talks.
SIPTU said butchers should receive a pay increase ahead of flexibility discussions.
The row is based on a pay rise granted to non-specialist staff working at meat counters who agreed to new work practices.
Butchers, traditionally better paid that their co-workers, sought a restoration of the wage differential.
Six Superquinn stores located outside the greater Dublin area have not so far been affected. However, butchers' counters at 13 outlets will remain closed today.
The Blackrock branch in Dublin which closed on Monday, opened for business yesterday.