Sources have revealed that the joint venture between General Motors and LG Energy Solution is working on a deal to raise wages at GM’s Ultium battery plant in Ohio, Reuters and Bloomberg report.

The news was corroborated by the United Auto Workers (UAW) labour union, which announced on its website that it had won an agreement to “immediately raise wages” by $3 to $4 an hour, as well as thousands of dollars of back pay for hundreds of workers.

UAW President Shawn Fain said: “After months of public pressure and worker organizing, Ultium was forced to take a first step towards economic justice for the workers who are powering GM’s electric vehicle future.”

The breakthrough for Ultium battery workers comes during the midst of tense ongoing negotiations between unions and the Detroit Three. UAW wants to see a 40% pay increase for its members.

The union has pushed to authorise votes on strike action, with Mr Fain commenting that UAW members were done “taking scraps.”

The contracts for both UAW and other union Unifor are set to expire simultaneously on 14 September. Chrysler parent Stellantis and GM have voiced concerns over union proposals.

GM recently admitted it faced some “startup challenges” with production around its EVs, including issues with battery module creation. If union workers vote for strike action, it would set the automaker back further.

So far there has been little headway during talks between the unions and the Detroit Three and the UAW and UNIFOR union memberships have voted overwhelmingly to authorise strike action if necessary.