If Tesco workers fail in their battle to protect pay and conditions, the "negative ripple effect" for all private sector workers would be "significant", the Mandate trade union, has warned.

The union, which is holding its biennial delegates conference in Galway on Sunday and Monday, is calling for union-wide support for Tesco workers.

About 1,000 long-serving staff at Tesco voted overwhelmingly on Friday for strike action over company plans to reduce their terms and conditions.

Tesco, which is the largest private sector employer in the State, has 14,500 staff in 149 stores. It is seeking to bring long-service employees’ pay and conditions into line with the rest of its workers. This would mean pay cuts of up to 35 per cent for this group, says the union. Tesco plans to implement the changes next month.

Tesco said it was disappointed at the result of Friday's ballot and would attend a conciliation conference at the Workplace Relations Commission.

Gerry Light, assistant general secretary at Mandate and organiser in the Tesco and Dunnes Stores sectors, said any retail worker who thought the outcome of the dispute didn't matter to them, was deluding themselves.

Tesco management’s aim was not limited to changing the terms and conditions of a group of workers, but was ultimately to “rid themselves of the union” to facilitate more rapid expansion and growth in profits.

“If one of the biggest private sector employers in the country, who happens to be a retailer, rids themselves of a unionised workforce in this way then the potential negative impact and ripple effect for all private sector workers and private sector trade unionism will be regressive in nature and significant in scale.”

An emergency motion, passed unanimously, calls on the union "to enlist the assistance and solidarity of all trade unions in Ireland to support Tesco workers in their struggle".

Patricia King, general secretary of Congress, said the Tesco workers had the "full support of the entire trade union movement".

Mr Light said the "long-standing battle for decency" for Dunnes Stores workers continued.

The union had "only last week" referred its claim for contracts guaranteeing a minimum number of hours sufficient to make a living wage, to the Labour Court. This move had been made possible by legislation enacted late last year which, said Mr Light, may yet be challenged by Dunnes Stores.

“If the legislation does fail a legal challenge then we must demand a more robust law to help workers fight their cause,” he said.