A union accuses the company of reneging on a promise not to cut jobs as it continues the integration of the SSE brand.
OVO Energy, which bought the household supply business of SSE for £500m just months ago, has announced plans to slash 2,600 jobs.
The company said its integration plans, including a drive for digital and investment in a zero carbon future, had been accelerated by the COVID-19 pandemic.
OVO said it had initially expected the moulding of the two companies to have taken a number of years but it hoped to achieve the cuts through volunteers though it could not rule out compulsory redundancies.
The GMB union accused the company of cutting its way to profitability as the industry suffers the effects of the government's default tariff price cap and falling wholesale energy costs.
Research by price comparison site Uswitch suggested home energy deals had fallen to their lowest since the summer of 2018.
OVO said of the roles affected by its cuts: “As part of the integration, the company will remove complexities and duplication by combining SSE Energy Services and OVO's home services, lettings business, metering, commercial efforts and support functions.
“It will continue to digitise legacy SSE processes and move the business onto a common set of systems to meet the demands of an increasingly digital consumer and a more agile workforce.
“To accommodate these changes, and as part of a move towards more flexible working the Selkirk, Reading and Glasgow Waterloo Street office locations will be closed.
“The employees in these sites will be able to either work from home or at an alternative office.”
The union Unison said plans to offshore a further 700 jobs to South Africa were abandoned by the company.
Stephen Fitzpatrick, OVO's chief executive, said: “Today is a very difficult day. We have a brilliant team here and this news isn't a reflection of anyone's work.
“What should have been a much longer process to digitise the SSE business and integrate it with OVO has been accelerated due to the impact of the coronavirus.
“We are seeing a rapid increase in customers using digital channels to engage with us, and in our experience, once customers start to engage differently they do not go back.
“As a result, we are expecting a permanent reduction in demand for some roles, whilst other field-based roles are also heavily affected.”
The GMB union accused the company of betraying its workforce.
National secretary Justin Bowden said: “Coronavirus outbreak or not, this is a massive betrayal of promises made to workers and politicians that the sale to OVO would not result in job losses.
“The COVID crisis and the SVT cap have affected the whole energy retail market but you cannot just cut your way out of a crisis in search of profit.”
By James Sillars