US President Joe Biden is pushing for tariffs to triple on Chinese steel and aluminium, as he seeks to boost union support in the swing state of Pennsylvania.In a meeting with United Steelworkers union members in Pittsburgh on Wednesday, Biden will call on trade representative Katherine Tai to triple the tariff on the imports from the current average of 7.5 per cent.

Biden’s campaign is trying to shore up support among union workers ahead of November’s US presidential election, in which Pennsylvania could play a decisive role.

 “It is important for us to get ahead of China’s new export surge and their continued pressure on prices that make it hard for American steel companies to compete,” said a senior US official, who added that the actions had “nothing to do with elections”.