General Motors (GM) and the United Auto Workers (UAW) announced on Wednesday a tentative labour agreement that could end a month-long strike that has paralysed the auto giant.

The UAW GM National Council, which includes local union chapters, was set to convene on Thursday and consider the agreement struck between GM and UAW leadership, the union said in a statement.

A majority of UAW members would then need to ratify the agreement.

The strike will continue until the council approves the proposed agreement. But union leaders also were to decide on Thursday whether to continue striking until all members voted, the UAW said.

Neither the UAW nor GM released details of the tentative deal that would end a strike that has now dragged into its fifth week, with mounting costs for both the company and workers.

Nearly 50,000 hourly workers have been on strike since September 16.

The full employment hit has been estimated at as many as 150,000 people throughout the industry, including tens of thousands of salaried GM workers and auto supply employees.

“The number one priority of the national negotiation team has been to secure a strong and fair contract that our members deserve,” said UAW vice-president Terry Dittes.

Dittes said union leaders would refrain from commenting on the details “out of respect for our members” until UAW GM leaders hear all the details.

A GM spokesman confirmed UAW’s announcement of a tentative deal and said “additional details will be provided at the appropriate time”.

GM said on the eve of the strike that its offer included more than $7 billion in investment to support more than 5,400 jobs. It also said it would pay a ratification bonus of $8,000 per worker.

A union source speaking on the condition of anonymity said the vote outcome was difficult to predict because around 40 per cent of the workers are fairly new to the company and have not lived through an industry downturn.