Walker served with distinction throughout the Thatcher government, carrying the brief for Wales, Energy and Food and Fisheries. As Energy Secretary, he was a key figure during the Miner’s Strike. Walker was Trade and Industry Secretary towards the end of the Heath government, but his major ministerial achievement was as the nation’s first Environment Secretary, a post he held from 1970-1972. His Waterways Act restored fish and plant life to rivers and lakes that had been declared biologically dead in the 1950s – a rare example of policy manifestly delivered. He represented the Worcester constituency from 1961 to 1992. His son Robin won the seat at the recent general election.