Jones was first elected as MP for North Durham in 2001 with a majority of 18,681. After becoming member of Parliament, Jones became a member of the influential Defence Select Committee, and also a member of the Labour Party's Parliamentary Committee. His Private Member's Bill, the Christmas Day (Trading) Act 2004, successfully passed Parliament, and came into force in December 2004. The Act makes it illegal for large shops to open on Christmas Day.
He was re-elected to the North Durham seat in the 2005 general election, with a majority of 16,781. He polled 64.1% of the vote. His campaigning on behalf of people who had coal health compensation payments deducted by unscrupulous claims handlers influenced the Compensation Act 2006
Jones was appointed Parliamentary Under Secretary of State and Minister for Veterans at the Ministry of Defence in October 2008.
In May 2010 Harriet Harman appointed Jones Shadow Minister for the Armed Forces, outside the Shadow Cabinet. He retained this position under Labour leader Edward Miliband and in Jeremy Corbyn's first appointment of shadow ministers in 2015.
He became a member of the special Select Committee set up to scrutinise the Bill that became the Armed Forces Act 2011.
He is Treasurer of the All-Party Parliamentary Group on Industrial Heritage.