John Huhne changed his plea to guilty as the first day of his trial was set to begin, The Guardian reported Monday.
He said afterward he would resign his seat in Parliament.
At a hearing last week, Huhne, the former energy secretary, pleaded not guilty to charges that he persuaded his wife at the time, Vicky Pryce, to take points assessed for a speeding violation that was actually his in 2003.
A traffic camera allegedly caught Huhne's car speeding between the Stansted airport and London in March 2003. During divorce proceedings in 2011, Pryce charged Huhne persuaded her to take the charges so he could avoid prosecution.
After his plea Monday, the 58-year-old Huhne was released on unconditional bail while he awaits sentencing.
Pryce, 60, has pleaded not guilty to similar charges, saying she was coerced by her husband.
Her case was adjourned until Tuesday. She also was released on unconditional bail.
Huhne stepped down from the Cabinet last year after he was charged.
Duggar sisters unveil Christian dating rules in new book
LGBT community has 'bullied the American people': Bachmann