The UK steel industry could be badly hit after US President Donald Trump confirmed plans for a 25% tariff on imports.
The measure – which Mr Trump said was aimed at protecting national security and American jobs – could trigger a full-blown trade war if the European Union responds with countermeasures.
Trade body UK Steel said the tariffs could have a “profound and detrimental impact” while the Community union demanded action to protect British jobs and avoid a “global trade war”.
Labour MP Stephen Kinnock, whose constituency in south Wales includes the giant Port Talbot steelworks, said Theresa May had “let down” British workers by failing to stand up to the US President.
Speaking in the White House with a group of workers, Mr Trump confirmed the tax on steel imports and a 10% tariff on aluminium in response to an “assault on our country” from cheap overseas metal.
There would be exemptions for North America Free Trade Agreement (Nafta) states Mexico and Canada and Mr Trump said other countries may be able to negotiate to avoid the tariffs.
Mr Trump said if his goals could be accomplished “by other means” the US will remain “open to modifying or removing the tariffs for individual nations as long as we can agree on a way to ensure that their products no longer threaten our security”.
“Such tariffs would have a profound and detrimental impact on the UK steel sector, which exported some 350,000 tonnes of products to the US in 2017, over 7% of its total exports.
“The UK sector is in the midst of a fragile recovery following years of considerable turmoil, it would be utterly devastating if this were to be undermined.
“Imposing such measures on US allies in the name of national security is difficult to comprehend.”
He said it was “vital” the EU and UK worked with the US administration on exemptions to the tariff.
But the industry fears the indirect consequences of Mr Trump’s actions, which could lead to cheap Chinese steel being dumped on European markets instead of sold to the USA.
Mr Stace said: “We must ensure our market is not now destabilised by millions of tonnes of steel diverted away from the US to the EU.
“We trust and hope that the UK Government will support such measures in due course.”
Roy Rickhuss, general secretary of steelworkers’ union Community said: “Donald Trump’s short-sighted strategy will put jobs at risk on both sides of the Atlantic.
“It is now more important than ever that Theresa May and Liam Fox use every bit of influence they have left in America to protect the jobs of British steelworkers.
“The steel crisis cost our industry thousands of jobs and the last thing we need now is a global trade war.
“The UK government must work with other EU nations to ensure we do not suffer the global consequences of Donald Trump’s actions.”
“Ever since Trump first announced punitive tariffs on steel and aluminium last week, the British steel industry, unions and steel MPs have been calling on her to make the case against these tariffs and for a UK exemption.
“Tonight we learnt that she has abjectly failed in that task.”
The EU’s trade commissioner Cecilia Malmstrom said the bloc should be excluded from the measures and she would meet US trade representative Robert Lighthizer to discuss the situation on Saturday.
A Government spokesman said: “The Government has been clear that tariffs are not the right way to address the global problem of overcapacity, which requires a multilateral solution.
“We will work with EU partners to consider the scope for exemptions outlined today and continue to work with all the sectors involved in this decision to robustly support our industries and demonstrate the importance of their high-quality products for US industries and security.”