Carmel Cacopardo has been appointed sustainable development spokesman for Alternattiva Demokratika.
Mr Cacopardo is experienced in planning, the use of land and politics, AD said.
Mr Cacopardo served as Mepa's assistant audit officer until some time ago but the planning watchdog's board decided not to re-appoint him.
He was a Nationalist Party candidate in three general elections, in 1987, 1992 and 1996, and sat on the PN's executive council for 12 years occupying the posts of information secretary, assistant general secretary and president of the administration council.