From 1990 until 1996, Lewis was a Deputy Director of the Conservative Research Department at Conservative Central Office (CCO). In the run-up to the 1992 General Election, CCO published detailed directories compiled by Lewis listing Labour MPs' and candidates' support for Left-wing causes. He continued in this role after his selection in February 1996 as prospective Parliamentary candidate for the new constituency of New Forest East, but in December of that year he resigned from CCO to campaign against Britain joining the single European currency. Only later did opposition to adopting the Euro become official Conservative policy.