British manufacturers have warned that proposed UK anti-dumping duties on Chinese aluminium extrusions are too low and threaten to cause a flood of imports, factory closures and job losses.

In its first new post-Brexit investigation, the Trade Remedies Authority, an independent government advisory body, has recommended setting duties on aluminium extrusions from a group of three large Chinese exporters that collectively account for 70 per cent of the country’s exports to the UK at 10.1 per cent.

Aluminium extruding is a process through which alloyed material is heated and moulded into shapes that have uses in the automotive, infrastructure and construction sectors. The EU has set tariffs on the products at 22.1 per cent, while the US has put them at 33.3 per cent.