Huhne, who will continue to serve in Parliament with the Liberal Democrat party, will appear in court later this month to face a criminal charge of perverting the course of justice.
The charge follows an eight-month police investigation into an allegation that Huhne persuaded his now ex-wife, economist Vicky Pryce, to accept a speeding penalty on his behalf in 2003, to avoid a driving ban.
Pryce, who is also charged with the same offense, split from Huhne in 2010 after he was exposed as having an affair with his public relations adviser Carina Trimingham.
A police inquiry was launched after Pryce was interviewed by The Sunday Times newspaper last year and alleged that Huhne had asked someone else to take the rap for the 2003 speeding offense, as he feared losing his diving license.
Huhne, who was energy and climate change secretary, denies any wrongdoing. In a letter sent to Cameron tendering his resignation, he said he would “mount a robust defense” against the criminal charges.
“I am innocent of these charges and I intend to fight this in the courts and I am confident a jury will agree,” Huhne told reporters Friday.
Cameron confirmed Huhne’s fellow Liberal Democrat Ed Davey, 46, would take over the position handling the climate change and energy ministry.
Davey had been a junior minister in the business department since 2010, responsible for the country’s postal service and consumer affairs. However, Cameron’s office insisted that did not signal there would be a new, pro-business approach toward the climate brief.
A lawmaker since 1997, Davey was honored by Britain’s Royal Humane Society in 1994 after he rescued a woman from the path of an oncoming train at London’s Clapham Junction — one of the country’s busiest railway stations.
Greenpeace director John Sauven said Huhne’s successor Davey was the right man for the climate change role.
“Given his strong track record in Parliament in voting for tougher climate change laws and stricter pollution controls for power stations, we are optimistic that he will be a robust and passionate advocate for the green agenda,” Sauven said.
The reshuffle marks another unplanned change to Cameron’s Cabinet, after Liberal Democrat David Laws stepped down in 2010 over an allowances row and following the dramatic departure of Defense Secretary Liam Fox, who resigned last year following a furor over a close friend who had posed as an aide.
Prosecutors said the offense Huhne and Pryce face carries a maximum sentence of life in jail, though those convicted typically face much more lenient punishments.
They were married for 26 years and had three children and two stepchildren together. The ex-couple is scheduled to appear at a London court on Feb. 16.
“We have concluded that there is sufficient evidence to bring criminal charges against Mr. Huhne and Ms. Pryce for perverting the course of justice,” said Keir Starmer, chief prosecutor for England and Wales.
The case relates to a speeding offense committed as a car used by the couple traveled from Stansted Airport, near London, to Huhne’s home in Clapham, south London in 2003, when Huhne was a member of the European Parliament.
Deputy Prime Minister Nick Clegg, who defeated Huhne to become Liberal Democrat leader in 2007, said in a letter that he hoped his colleague would return to a key role in government “as soon as possible.” The Liberal Democrats are the junior member in Britain’s coalition government.
Cameron, leader of the Conservative Party, wrote a frostier note to Huhne, saying he had “made the right decision under the circumstances” to step down.
