Jonathan Martin, the head of BBC Sport, retained Walker's services for the corporation's coverage of the BTCC after the latter's rolling contract expired with them in May 1997. Walker opted not to renew his contract with the BBC in 1998 to focus on ITV's broadcasting on Formula One and he did not want to frequently commute to London to record commentary of the BTCC. There were a few Grands Prix between 1978 and 1996 that Walker did not commentate on while employed by the BBC, usually as a result of his commentating elsewhere. Some of these included the 1979 Belgian Grand Prix and 1988 Hungarian Grand Prix (when Simon Taylor deputised for him), the German Grands Prix of 1981 and 1984 (both commentated on by Barrie Gill), and the 1985 German Grand Prix (Tony Jardine).