Unions fear around 1,700 jobs are set to be cut by energy firm Ovo.
An announcement is expected from the company on Thursday.
The Unite union said it warned in 2020 that Ovo was taking a risk when it took over the retail base of energy giant SSE.
General secretary Sharon Graham said: “We will do everything in our power to defend our members’ jobs.
“All and every option will be on the table. As a first step the company must now open the books to union experts.
“We will not sit by and watch our members being made to pay the price of the pandemic.”
The company had to apologise earlier this week after an email was sent out to customers, advising them to keep their heating bills low by “having a cuddle with your pets” or eating bowls of porridge.
Unite national officer for energy Simon Coop said: “We warned the directors about blundering into the SSE takeover.
“In recent years the same directors have plundered the accounts for amounts estimated to be touching £5 million.
“Ovo must be subject to severe scrutiny before the union decides on our next moves, but if they move to compulsory redundancies they will be fully opposed by the union.”
Comments & Moderation
Readers’ comments: You are personally liable for the content of any comments you upload to this website, so please act responsibly. We do not pre-moderate or monitor readers’ comments appearing on our websites, but we do post-moderate in response to complaints we receive or otherwise when a potential problem comes to our attention. You can make a complaint by using the ‘report this post’ link . We may then apply our discretion under the user terms to amend or delete comments.
Post moderation is undertaken full-time 9am-6pm on weekdays, and on a part-time basis outwith those hours.
Read the rules here