The EU has announced plans to hike tariffs on imported steel in a move the UK’s steel industry has said could be “perhaps the biggest crisis” it has ever faced.

The commission has set out plans to cut the amount of steel that can be imported into the bloc by half – beyond which the new 50% tariffs will apply.

The EU is the UK’s most important export destination for steel, worth nearly £3bn and representing 78% of steel products made in the UK for overseas markets.

The commission has come under pressure from some member states and their steel industries, who have been struggling to compete with cheap imports from countries like China and Turkey.

The EU is proposing to reduce tariff-free quotas for imports to 18.3 million tonnes a year – a 47% reduction from 2024 levels.

The new measures will come into force early next year, but will first need to be approved by the majority of EU member states and the European Parliament.

“We have global over capacity, unfair competition, state aid, and undercutting in prices and we are reacting to that”, Stéphane Séjourné, the European Commission’s executive vice president for prosperity and industrial strategy.

“Eighteen thousand jobs were lost in the steel sector in 2024. That’s too many, and we had to put a stop to that”, he told a news conference at the European Parliament in Strasbourg.

The announcement is another blow to the UK steel industry, after a proposed deal to eliminate tariffs on UK steel exports to the US was put on hold indefinitely in September.

Speaking on his way to India on Tuesday, the prime minister said there was “strong support” from the government for the British steel industry, which could be severely impacted by EU tariffs.

“I’ll be able to tell you more in due course, but we are in discussions as you’d expect”, Sir Keir Starmer said, refusing to go into the details of any discussion, including whether the UK was seeking exemptions.

Responding to the announcement, the director general of UK Steel, Gareth Stace, said the government “must go all out to leverage our trading relationship with the European Union to secure UK country quotas or potentially face disaster”.

He also cautioned now against the EU’s measures “redirecting millions of tonnes of steel towards the UK”, something which could be “terminal for many of our remaining steel companies”.

The Community Union, representing UK steelworkers, called the measures an “existential threat” to the industry.

In a statement, the Department for Business said it was “pushing the European Commission for urgent clarification of the impact of this move on the UK”.

“It’s vital we protect trade flows between the UK and EU and we will work with our closest allies to address global challenges rather than adding to our industries’ woes”, Industry Minister Chris McDonald said.

“This government has shown its commitment to our steel industry by securing preferential access to the US market for our exporters, and we continue to explore stronger trade measures to protect UK steel producers from unfair behaviours.”

The government said the industry minister will meet steel representatives on Thursday to discuss their concerns.