Coaker served as a district councillor for the Cotgrave Ward in Rushcliffe, Nottinghamshire from 1983 to 1997 and was leader of the Labour group on the council between 1987 and 1997. He contested the Rushcliffe constituency seat in 1983. He contested Gedling in 1987 and 1992 before defeating Andrew Mitchell in the 1997 election, becoming the first Labour MP to win the Gedling seat. After a number of Parliamentary Private Secretary roles, Coaker became a government whip in May 2005 having been an assistant whip since June 2003. He served as a Minister of State at the Home Office between 2008 and 2009 before being moved to take up the role of Minister of State for Schools and Learning between 2009 and 2010. Following the Labour defeat at the 2010 General Election, Coaker was appointed as Shadow Secretary of State for Northern Ireland in October 2011. Coaker joined dozens of shadow ministers in resigning from his position on 26 June 2016 in Labour's parliamentary disquiet over the leadership of Jeremy Corbyn. He supported Owen Smith in the failed attempt to replace Jeremy Corbyn in the 2016 Labour Party leadership election.
Expenses scandal
Coaker was found to have claimed large sums every month in cash for his second home without submitting any receipts. Over the course of four years, he claimed £3,425 for cleaning, £6,320 for services and maintenance and £5,205 for repairs. This was initially for his semi-detached home in Cotgrave, and then for his one-bedroom flat in Kennington in London. A spokesman for Coaker subsequently stated that expenses were claimed in accordance with the rules administered by Commons fees office at the time.
Political positions
Coaker supports the modernisation of the UK Trident missile system, and Britain's membership of NATO. He supports the multilateral disarmament of nuclear weapons. Coaker belongs to the Labour Friends of Israellobby group. Shortly after being appointed Minister for Drugs and Crime Reduction in the May 2006 reshuffle, he revealed to the Coventry Evening Telegraph that he had had "one or two puffs" of cannabis as a student but did not enjoy it. His admission was made during a nationwide tour to evaluate the effectiveness of the government's drugs strategy. He also supports people taking part in shooting sports and angling. In January 2010, Coaker apologised for remarks that misled MPs. He had earlier told MPs that 70 police officers were hurt as a result of a global warming protest at Kingsnorth power station. In fact there were only 12 injuries that were legally reportable with just four of those involving contact with another person. The remaining eight injuries included "wasp sting", an injury while "sitting in a car", and an officer succumbing "to sun and heat". There were 68 injuries in total with the rest being treated by first-aiders at the scene. The whole operation had involved more than 1,000 officers.
Personal life
He married Jacqueline Heaton on 23 December 1978 in Basford; the couple have a daughter and a son. He supports Tottenham Hotspur. His wife, who is a teacher, was a town councillor in Cotgrave, where they live in the district of Rushcliffe.