Ed Davey, the new Energy Secretary, will this week launch a powerful new body charged with saving millions of homes and businesses money on their heating and electricity bills.
In the first sign of his intention to use his cabinet promotion to be a "consumer champion", Mr Davey is expected to argue that going green does not necessarily need to cost more – a move that will win the support of the Chancellor, George Osborne. The new Energy Efficiency Deployment Office (EEDO) will signal that a reduction in demand for energy is "equally important" as the need to increase supply.
Mr Davey moved to the Department of Energy and Climate Change on Friday, when Chris Huhne resigned after being charged with perverting the course of justice over claims he asked his former wife to accept speeding penalty points on his behalf.
Government insiders sought to dispel concern among green campaign groups that Mr Huhne's departure would further weaken the coalition's green agenda, at a time when the Treasury has complained that environmental regulations and rising costs are stalling economic growth. "I wouldn't pretend Ed Davey was a household name," said one source. "But he has been at the top table for Lib Dem policy for a long time."
Mr Davey has a varied CV: after attending the same school as Ed Balls, he was at Oxford University with David Cameron. He once worked in a pork pie factory; and in 1994 he received bravery awards for saving a woman who had fallen on to the line in the path of a train at Clapham Junction.
He is understood to be ready to take a tougher line with energy firms, having spent almost two years at the Department for Business, where he forced through Royal Mail privatisation and reform of employment law. A Europhile who is admired by Tories, he is known to carry a small laminated card detailing the voting power of EU countries in order to identify allies for policies that are in Britain's interests. He speaks French, Spanish and German.
On Monday, Mr Davey will make a visit to a green-energy project with Nick Clegg, the Deputy Prime Minister, to put his stamp on his new job. And later this week ministers will announce that the EEDO will be "at the centre of a new drive to improve the way we use energy across the UK".
Tory ministers, in particular, hope Mr Davey will take a higher-profile stance against rising energy bills, which Labour has used to strike a populist chord by attacking "rip-off" firms. In the last quarter of 2011, domestic gas prices were 23 per cent higher than a year earlier and electricity charges were up 15 per cent.
In opposition, Mr Davey accused energy companies of using various tactics to fleece consumers, "mostly targeted on the poor", and warned that a focus on nuclear power risked investment in renewable technology.
In government he has championed giving customers more information about their bills and has also called for homeowners to be able to group together to secure bulk discounts on energy-efficient products.