The Department of Energy and Climate Change (DECC) is to accept cut to an annual budget of around 21% ahead of next week’s spending review, media reports have claimed.

Chancellor George Osborne is to announce his autumn statement next Wednesday at the same time as a review of government departmental spending as HM Treasury’s attempts to cut the UK’s deficit redouble.

Earlier this year Osborne wrote to all government departments, requesting them to draw up plans to cut their budgets by as much as 40% with the chancellor targeting any perceived waste at Whitehall.

In June Osborne addressed DECC to inform the department that its budget would be cut by £70 million for the 2015/2016 financial year, which the department later clarified would be sourced primarily from cuts to energy efficiency subsidies.

However reports from publications such as the Financial Times and Huffington Post claim that DECC is one of five departments to formally accept budget cuts of an average of 21% – roughly half what Osborne originally requested and less than what other bodies, including Defra, accepted last week.

The department has already set the wheels in motion for around 200 jobs to go under a voluntary exit scheme, which would see its headcount fall from 1,600 to around 1,400.

Permanent secretary Stephen Lovegrove confirmed the move last week, describing it as a repurposing of teams within DECC that have largely finished their work such as those who had worked on the Electricity Market Reform. Other staff will be seconded to the National Infrastructure Commission.

DECC could not be reached for comment at the time of publication.