Workers at more than 70 Tesco outlets across Ireland will strike on Monday in a dispute over pay and conditions.

Mandate members at the company voted in favour of industrial action last month after the retailer proposed new contracts with reduced rates for longer-serving employees.

The trade union said the change would see staff hired before 1996 having to accept pay cuts of between 15% and 35%, roster changes, lower Sunday premiums, and a reduction in overtime and annual bonuses.

Affected workers who did not accept voluntary redundancy packages were offered a once-off compensation payment. 

Mandate said pickets will be placed at Tesco stores on Monday morning following confirmation that the company “will be implementing pay cuts and changes to conditions of employment for up to 300 of their staff”.

The union said Tesco could prevent the strike by "withdrawing its threat to cut workers’ wages without agreement" or by attending the Labour Court for a hearing on the dispute.

Gerry Light of Mandate said: “Tesco management are forcing changes to contracts for workers employed before 1996.

“These changes will seriously undermine living standards for our members who have mortgages and other commitments which were made on the back of their conditions of employment over the last 20 to 30 years.”

Tesco said in a statement that it was disappointed with the announcement.

"We remain committed to reaching agreement on this issue and earlier this week we formally tabled a generous proposal for compensation for colleagues in scope," the company said.

"We need to make this change in order to improve our customer service at our busiest times of the week."