Tate & Lyle Sugars has been forced to lay off 30 members of staff and stop weekend production at its London refinery because of EU import restrictions.

The 800 workers at the Silvertown refinery were informed on Tuesday of the job cuts and the abolition of weekend shifts, which will affect 65 people and end 40 years of continuous production at the site.

“This is a sad day for us, and is in no way the fault of our skilled and dedicated workforce. It is entirely due to the constraints on our raw material supply created by the European Commission,” said Tate & Lyle Sugars president Ian Bacon.

The company has had to pay tariffs of up to €339 per tonne to import sugar due to shortfalls in supply from the limited number of African, Caribbean and Pacific states that have tariff-free access to the EU market.

The upshot of the restrictions is that Tate & Lyle Sugars has only been able to import enough sugar at acceptable prices to keep the Silvertown refinery on the Thames running at 60% over the past year. Even at the reduced output levels, the company has had to fork out about €15m in tariffs.

Sir Robin Wales, mayor of Newham, where the refinery is situated, said the news was a terrible blow to staff and urged action to give Tate & Lyle Sugars, which built the refinery in 1878, a fair chance to compete.

“I have written to both the European Commission and Defra to urge them to act to protect the long-term future of the company,” he said.