British Gas to axe 680 jobs in Oldbury site closure plan
British Gas is planning to close an office and call centre with the loss of more than 680 jobs.
The firm said proposals to close its Oldbury site was part of a strategy to improve service and reduce costs to ensure competitive prices.
Customers now increasingly prefer to contact British Gas online, the company said.
The GMB union said the firm "sees staff as pawns to be sacrificed when it suits".
The 684 proposed job losses were understood to be part of thousands of job cuts announced in July by parent company Centrica, which owns other energy businesses.
'Out of the blue'
British Gas said it would consult staff and would "explore redeployment opportunities" if the closure was confirmed.
A worker from the Dudley area, who wished to remain anonymous, told BBC News she is on maternity leave and only learned about the cuts from watching the news on television.
"I turned on the TV and thought, no... it's not true.
"I phoned my boss and he called back and he said yes, it is a proposal at the moment that we are going to be closing down.
"I am obviously very worried and thinking what am I going to be returning to.
"It's just out of the blue and how is the prime minister going to help 684 people find new jobs?"
Unite said British Gas was looking at relocating its Oldbury operation between Uddingston, in Glasgow, Leicester and Stockport, Greater Manchester, with the plan to create further roles there, but most people "may not want to relocate".
Brian Strutton, national officer for the GMB, said the announcement came "completely out of the blue" as the office had been performing well.
But he added: "All the while the company's top brass on their multi-million-pound pay packages have been harbouring secret plans to shut it down."
Unison said the scale of cuts would make "compulsory redundancies hard to avoid".
During Prime Minister's Questions, David Cameron told MPs the government stood ready to help those affected.