After leaving university, Walker set up his own internet business, before pursuing a career in the City of London with the financial communications company Finsbury.

Walker has campaigned in three elections, working for Secretary of State for Health Stephen Dorrell in 1997, for Richard Adams, the Conservative Candidate for Worcester in 2001, and as press officer for Oliver Letwin, then Shadow Chancellor, in 2005.

[5] Walker was one of a small group of Conservative MPs who rebelled from the party line and voted in favour of an in/out referendum on Britain's membership of the European Union.

[10] Walker has supported a number of cross party initiatives on making credit unions available in post offices as well as helping them to compete with larger lenders.

[12] In July 2014, Walker called on Prime Minister David Cameron to use "every tool in the box" to de-escalate the violence in Gaza, and bring both sides to the table.

[13] Later that year, Walker campaigned for a two-hour train service from Worcester to London, citing benefits to local constituents and businesses.

[17] After the election, Walker was made PPS to Secretary of State for Education Nicky Morgan and also sat on the House of Commons Select Committee for Administration.

On 9 April 2011, Walker married Charlotte Keenan,[29] former chief executive of the Tony Blair Faith Foundation,[30] currently managing director at Goldman Sachs.