More than 17,000 Tata Steel employees will strike on 22 June in an ongoing dispute over the organisation’s pension scheme changes.
The action will include a ban on overtime and work-to-rule will be carried out next week by employees.
The dispute is over the closure of the steel workers’ final salary pension scheme, which has a deficit of £2 billion, and rules that could see employees retiring at 65 instead of 60.
However, the organisation is working on plans to amend its decision to close the British Steel Pension Scheme (BSPS) to future accrual and alter entitlements for existing members.
As of December 2014, the BSPS had 143,000 members, with 17,004 employee members and 91,264 pensioner members.
Tata employees will go on strike across its four sites in Wales in Port Talbot, Newport, Flintshire and Carmarthenshire, as well as sites in England including Corby, Hartlepool, Rotherham, Scunthorpe, Teesside and York.
It is the first national steel strike in more than three decades.
A Tata Steel spokesperson said: “We have been trying to develop an affordable and sustainable pension scheme for employees so we are very disappointed by the announcement on strike and industrial action.
“Everyone agrees that changes need to be made to resolve the challenges facing our pension scheme, which has a projected shortfall of over £2 billion.
“We have, over the last few months, listened carefully to our employees during an extensive consultation process involving thousands of employees.
“We will soon be announcing new measures which will lessen the impact of the proposed pension changes, particularly on our longest-serving employees nearing retirement age.
“We hope that these important changes to our proposals will be welcomed by employees and that the trade unions reconsider industrial action.”
Paul Reuter, national officer at Unite, said: “We have offered the savings the [organisation] says it needs. Instead Tata Steel UK wants to financially penalise its workforce and force it to work another five years to get their full pension.”
Roy Rickhuss, chair of the National Trade Union Steel Co-ordinating Committee, and general secretary of the Community trade union, added: “Tata has given us no option but take industrial action. The organisation has not shown any willingness to return to meaningful negotiations to find an end to this dispute.
“An overtime ban and work-to-rule will cause massive disruption to Tata’s operations and severely limit production. The organisation could avoid this by returning to the table. But in the meantime all the unions will also be making preparations for a national day of strike action on 22 June.”