VICKY PRYCE, one of the country's top economists, quit her job as a government adviser because of the conflict of interest created when her husband, Chris Huhne, joined the Cabinet as Climate Change Secretary.  at the same time, however, the Liberal Democrat MP was harbouring a conflict of interest of his own: a relationship with his 44-year-old former aide, Carina Trimingham. Mr Huhne ended his 26-year marriage, and set up home with Ms Trimingham. So Ms Pryce was bemused to receive a call from a headhunter touting the post of chief economist and director of analysis, with a salary of ?100,000, at her former husband's department. Ms Pryce, 57, has turned down the job.