Thousands of workers at energy giant Centrica face cuts to their pay and conditions, according to unions.

The GMB said it has started talks with the company on planned changes.

National officer Justin Bowden said: “GMB has begun talks with Centrica who, on top of the 5,000 job losses announced in June, now want to make cuts to pay and terms and conditions.

“GMB members have worked throughout the coronavirus crisis to maintain services to customers and delivered millions of meals to the elderly and vulnerable. It now appears Centrica have used this period planning cuts to the earnings of loyal staff.

“It remains to be seen whether the latest leadership of Centrica thinks it too can cut its way out of crisis where its predecessors have failed, or if it has a plan for growth and the ability to negotiate.”

Sue Ferns, deputy general secretary of Prospect, said: “Retail energy businesses face extreme financial pressure at the moment but this will still be a shock to Centrica’s dedicated workforce.

“The company has issued advance notice of redundancy to all staff and recognised unions. While it states that it hopes to agree change, this threatens to impose lower employment conditions on all staff if they do not agree – this is an extreme step.

“Prospect aims to negotiate the best future for its members, other Centrica staff and the business.

“Prospect believes that the twin pressures of Covid-19 and the retail price cap are forcing change on all energy businesses with the financial burden falling on staff.

“Prospect wrote to Ofgem asking for the price cap to be adjusted to mitigate short-term financial pressure on companies. With job losses coming through it is even more important that Ofgem take urgent action to mitigate the financial impact of Covid-19 and safeguard jobs.”

A Centrica spokesman said: “We’ve been open about the changes we need to make to win back customers, grow our company and protect jobs in the long run.

“Our employees’ base pay and pensions will be protected but simplifying and modernising their terms is essential if we’re to become more flexible and price competitive.

“We have over 80 different employee contracts with 7,000 variations of terms, many of which are outdated and stop us delivering for customers.

“We want to continue with constructive talks and the s.188 notice provides an option of last resort if it turns out we can’t work together to achieve this.

“We understand the impact this will have on colleagues and this is not an option we want to use but we must make these changes and we must conclude these talks before the winter period.”

Unison assistant general secretary Christina McAnea said: “This is disgraceful behaviour. British Gas might be struggling financially but it’s no way to treat loyal staff, many of whom have been with the business for years.

“Employees have worked hard throughout the past few months to ensure customers are well-served, despite the pandemic. This is not how company directors should repay them.

“With so many jobs being lost across the UK, staff will feel betrayed by the business. Unions will be doing everything in their power to win employees a better deal.”