Tata is to take steps to cease operations at its steel plant in Port Talbot earlier than planned because of a strike by Unite, workers have been told.
The company had been planning to shut down one of the blast furnaces by the end of June and the second one by September.
But workers at the South Wales site have been told that because of the strike by members of Unite, from July 8 Tata can no longer be assured of sufficient resources being available to ensure safe and stable operations.
A message to employees said: “Therefore, we are left with no alternative but to take preparatory steps to cease operations on both blast furnaces and safely isolate them no later than July 7.”
Unite called the strike in protest at plans to switch to a more environmentally friendly way to produce steel, with the loss of thousands of jobs.
Tata has also launched legal action against Unite’s ballot.
A Tata Steel spokesperson said: “Following the announcement by Unite Union to unilaterally call strike action from 8 July, Tata Steel is unfortunately forced to commence legal action to challenge the validity of Unite’s ballot.
“In the coming days, if we cannot be certain that we are able to continue to safely operate our assets in a stable fashion through the period of strike action, we will not have any choice but to pause or stop heavy end operations (including both blast furnaces) on the Port Talbot site.
“That is not a decision we would take lightly, and we recognise that it would prove extremely costly and disruptive throughout the supply chain, but the safety of people on or around our sites will always take priority over everything else.
“The company again calls for Unite to withdraw its industrial action and join Community and GMB unions in giving consideration to the company’s proposed Memorandum of Understanding, which puts forward a wide-ranging proposal including generous employee support packages, training and skills development.”
The Tata spokesperson added: “We understand the impact of our restructuring will have on many employees and contractors, but we remain committed to a just transition and — pending a Government-backed grant funding agreement — to the £1.25 billion investment in low-CO2 steelmaking, which will ensure Tata Steel has a long and sustainable future in the UK.”
Unite general secretary Sharon Graham said: “Unite is fighting for the future of the steel industry. We have secured serious investment from Labour to safeguard jobs.
“Tata putting out a statement to shut or pause its blast furnaces three months earlier than they intended to is the latest in a long line of threats that won’t deter us.
“The Unite campaign is not about selling jobs, it’s about securing the long-term future of steel making in this country for thousands of workers in Port Talbot and South Wales.
“We call on the real decision makers in Mumbai to take hold of this dispute, sit down, negotiate and realise that the investment secured will be good for the company and workers.”
Charlotte Brumpton-Childs, GMB national officer, said: “This is a sad day for steel. Tata must step back from this irreversible decision and safeguard steelmaking assets. There’s a General Election in days that could change everything so much.
“We know there is a future for steelmaking in South Wales. That future must be preserved. GMB’s next actions will be decided by our members.”
Community and the GMB unions are also campaigning against the plans but have ruled out taking industrial action before the General Election.
The unions expect an incoming Labour government to hold emergency talks with Tata to discuss alternatives to its proposals.
Tata has made it clear it is pressing ahead with switching from blast furnace production to an electric arc, as other steel companies are doing.
Tata says it is losing £1 million a day at Port Talbot which it has warned is unsustainable.
The company offered an enhanced redundancy package to workers affected by the plans, but this was reduced after Unite members started industrial action short of a strike earlier this month.