LONDON — Former British Energy Secretary Chris Huhne said he’ll step down as a Liberal Democrat lawmaker after pleading guilty in a London court Tuesday to perverting the course of justice in relation to a speeding offense.

Huhne, who had pleaded not guilty to the charge last week, resigned from the Conservative-led government in February 2012 after becoming the first serving British Cabinet minister to be charged with a serious criminal offense in modern times.

“Having taken responsibility for something which happened 10 years ago, the only proper course of action now is to resign my Eastleigh seat in Parliament, which I will do shortly,” Huhne told reporters outside Southwark Crown Court in London.

The announcement that he’ll quit the House of Commons paves the way for a special election in his swing seat that will see candidates of both coalition partners vying for victory.

The vote will highlight the growing rifts between the parties over policies from taxes through Europe to same-sex marriage as they position themselves for the next general election in May 2015.

Both Huhne, 58, and his ex-wife Vicky Pryce, were charged last year by British prosecutors after it was alleged that Huhne committed a speeding offense and coerced his then wife to take the penalty points so he could avoid disqualification, according to the indictment.

She has pleaded not guilty and her trial will begin Wednesday.

‘No Illusions’

Perverting the course of justice carries a maximum sentence of life in prison, according to a Crown Prosecution Service spokesman.

“You should be under no illusions whatsoever as to the sort of sentence you are likely to receive,” Judge Nigel Sweeney told Huhne during Tuesday’s hearing.

Huhne pleaded guilty after losing a bid to have the case dismissed. Sweeney rejected the applications in a written ruling issued last week and made public today.

Huhne won the contest for the Eastleigh constituency in southern England from the Conservatives by 3,864 votes out of 53,650 in the May 2010 general election, after which the two parties formed their coalition.

The Liberal Democrats and Tories took 85.8 percent of all votes in the district, with Labour, now in opposition, in third place with 9.6 percent. Liberal Democrats have held the seat since winning it from the Conservatives in a 1994 special election, with Huhne taking over in 2005.

Negative Campaigning

“There will be a fair amount of negative but not nasty campaigning in Eastleigh between the Tories and Lib Dems as it points forward to what will happen in 2015,” Tim Bale, professor of politics at Queen Mary University London, said in a telephone interview. “They have to start to find ways to differentiate from each other but they’ve got to work together for another couple of years.”

Both governing parties have lost support nationally since the general election, as the deepest budget cuts since World War II and policy U-turns have boosted backing in opinion polls for Labour and the anti-European Union U.K. Independence Party.

One Tory lawmaker described the Eastleigh vote as a chance to retaliate against the Liberal Democrats for scuppering a bid last week by the Tories to cut the number of House of Commons lawmakers and redraw electoral-district boundaries to ensure they are of more equal size.

That would have helped the Conservatives in 2015.

‘Exact Revenge’

“At least we get an early opportunity to exact revenge on the Lib Dems over boundaries,” Alec Shelbrooke told Sky News television.

Bookmaker William Hill Plc made the Conservatives 1-2 favorites to win the seat, meaning that a successful 2-pound bet would win 1 pound plus the return of the stake. The Liberal Democrats were 6-4 to retain it.

The seat “could be tricky for the Lib Dem candidate to defend in the current climate,” Hill’s spokesman, Graham Sharpe, said in an emailed statement.

As late as December, allies of Huhne told the Mail on Sunday newspaper that he might challenge Nick Clegg for the role of Liberal Democrat leader as the deputy prime minister’s poll ratings fell.

Huhne challenged Menzies Campbell to head the party when Charles Kennedy quit in January 2006, finishing second. Clegg, who didn’t seek the role then, beat Huhne when Campbell stepped down in 2007.

“This is obviously an extremely serious matter and it’s essential that the legal process is now allowed to run its course,” Clegg told reporters. “I am shocked and saddened by what has happened, but I believe that Chris Huhne has taken the right decision in resigning.”

Prime Minister David Cameron’s spokesman, Jean-Christophe Gray, declined to answer reporters’ questions on whether Huhne should repay the severance package of 17,000 pounds ($27,000) he claimed when he quit the Cabinet.