Derek was born and bred in the Constituency and studied at Halton College of Further Education ( Riverside College).

Dismayed by the Labour Government’s defeat in the 1979 General Election, Derek joined the Labour Party. By the age of 21 he was elected to represent the Broadheath and Kingsway wards on Cheshire County Council, winning the seat back from the Tories. That election saw the Conservatives lose their majority on the Council for the first time.

In a by-election in 1984 Derek won the Halton View ward seat on Halton Borough Council where he focused on his main concerns: housing and poverty. By the age of 27 he had become Chairman of the Housing Committee where he vigorously pursued a policy of modernising Halton’s housing stock and increased tenant participation. He later served as Chairman of Finance and led on Education during Halton’s successful bid to become a Unitary Authority.

In 1997 Derek succeeded the Rt Hon Gordon Oakes as Member of Parliament for Halton winning with a record majority of over 23,000. On 10th June 1997 Derek made his maiden speech in the House of Commons in the Education (Schools) Bill debate (read Derek’s maiden speech.)

Derek has served as a member of the Public Accounts Committee. He has been Parliamentary Private Secretary to two ministers, Firstly, to Rt Hon Helen Liddell who was then Minister of State for Energy, and then to Rt Hon Stephen Byers when he was Secretary of State for Transport and the Regions. In June 2002 Derek became a Government Whip.  In December 2004 Derek was appointed as Parliamentary Under Secretary of State for Schools at the Department for Education and Skills. After the May 2005 General Election, Derek was assigned the role of Parliamentary Under Secretary of State at the Department for Transport. In September 2006 Derek was appointed as Under Secretary of State for Defence and Minister for Veterans at the Ministry of Defence.  Derek left the Government in October 2008, and became a member of the Children, Schools & Families Select Committee.

Derek served as a Shadow Health Minister in October 2010, returning to the back benches in summer 2011. From 2013 until 2015 he sat as a member of the Defence Select Committee. Derek later returned to the Defence Select Committee and is currently a member of it.

Since the General election in July 2024, he has been appointed by the Prime Minister as Leader of the UK Delegation to the NATO Parliamentary Assembly and a member of the Intelligence and Security Committee. He is also a member of the Joint Committee on National Security Strategy.

Derek’s main interests outside of politics include hill walking, military history, football and Rugby League.