Bates first worked as a science teacher at
Humphrey Perkins Junior High School,
Barrow on Soar; then at Belvidere Secondary School, Shrewsbury, from 1970 to 1975; he became head of general science at The Grove School,
Market Drayton, 1975–77. In 1977 he left teaching to become a farmer and took up campaigning on behalf of agriculture and rural communities. Bates was chairman of the
National Farmers Union (NFU) Llanfair Caereinion Branch from 1983 to 1985 and Chairman of the County Livestock Committee, 1988–1991. He instigated and chaired the NFU County Public Affairs Committee in 1990 and was the NFU County chairman in 1991. In 1994 Bates became involved in local politics as a Liberal Democrat County Councillor for
Dyffryn Banw, where he started a community regeneration scheme as Chairman of the Llanfair Town Forum, which successfully obtained Market Towns Initiative status. He also produced and presented the Radio Maldwyn farming programme and organised a scheme for students to visit farms from 1994–5. He was an NFU elected delegate 1995. He was founding Chair of Primestock Producers Cymru, a national farmers cooperative, and also helped to found Montgomeryshire Rural Enterprises in 1997. In 1999 Bates was elected as Welsh Assembly Member for
Montgomeryshire. He announced in the summer of 2009 his intention to retire at the
2011 election. Bates resigned from the party before the Welsh Liberal Democrats could convene a committee of enquiry and served the remaining months of his term of office in the Assembly as an independent. He did not stand for re-election. Bates died from cancer on 29 August 2022, at the age of 74. ==National Assembly==