Cunningham was the Labour MP for Copeland from 1970 until 2005, when he stood down at the General Election. Copeland is the constituency that includes the controversial nuclear plant at Sellafield. During his time in Parliament he was one of the most vocal pro-nuclear MPs and he was known as "Nuclear Jack" and was President of the "Friends of Sellafield Society."
In 1999, the Ecologist Magazine noted: "Dr Jack Cunningham has gone further than almost any other Labour politician in supporting nuclear power. As MP for Copeland (previously Whitehaven) since 1970, it is not surprising that Cunningham has developed a relationship with the nuclear industry - the Sellafield plant is based in his constituency. It is the extent, however, of his pro-nuclear stance and the intimacy of his relationship with British Nuclear Fuels (BNFL) that has rendered the objectivity of his decisions as a Minister open to question".
He listed as one of his most important achievements as an MP as "Leading the campaign to safeguard the future of Sellafield and the 16,000 jobs it sustains". He was made a life peer and is now Lord Cunningham of Felling. Cunningham is still a Patron of SONE.
According to its website, Cunningham is one of the chairs of the Transatlantic Nuclear Energy Forum. The forum has paid for his travel to the US - See below. He discloses a number of overseas visits on nuclear issues paid from various sources:
- 3-6 June 2003, to USA. Transport and accommodation provided by USA Department of Energy and BNFL Inc. (Registered 13 July 2003)
- 22-26 November 2003, to Washington DC, to discuss nuclear policy issues. Travel and accommodation costs were met by Sovereign Strategy Ltd. (Registered 19 December 2003)
- 12-18 June 2004, to Washington DC, USA, to discuss nuclear policy issues. Travel and accommodation costs were met by Cumbria Inward Investment Agency. (Registered 27 July 2004)
- 20-23 September 2004, to Washington DC, to discuss nuclear policy issues. Travel and accommodation costs were provided by the Transatlantic Nuclear Energy Forum. (Registered 15 November 2004)
- 10-15 October 2004, to Amelia Island, Florida, USA, to speak at the Monitor Conference on Nuclear Decommissioning. Travel and accommodation costs were provided by the conference organisers. (Registered 15 November 2004)
Cunningham first declared an interest in lobbying firm Sovereign Strategy Ltd in 2002. He described the firm as 'a management skills company'. His involvement brought his external jobs to three which he kept until he retired as an MP in 2005:
- Partner, Brinkburn Associates (political and public policy consultancy).
- Anderson MacGraw (Partner) (political and public policy consultancy).
- Sovereign Strategy Ltd. (non-executive) (a management skills company).
In 1997, Friends of the Earth reported how "Dr Jack Cunningham MP, Secretary of State for Agriculture, Fisheries and Food, is actively opposing two wind farms being proposed within his constituency on the grounds of visual intrusion despite the presence of Britain's largest nuclear facility, British Nuclear Fuels Ltd at Sellafield, only a few miles away.
PPS to James Callaghan as Foreign Secretary and Prime Minister 1974-76; Parliamentary Under-Secretary for Energy 1976-79; Shadow Environment Secretary 1983-89; Shadow Leader of the House 1989-92; Shadow Secretary of State for: Foreign and Commonwealth Affairs 1992-94, Trade and Industry 1994-95, National Heritage 1995-97; Minister of Agriculture, Fisheries and Food 1997-98; Minister for the Cabinet Office, and Chancellor of the Duchy of Lancaster 1998-99
- City of London Corporation - former paid adviser
- North-East Sustainable Resources Board - chairman 
- Aeternum Capital Management LLP - paid adviser 
- Brinkburn Associates (political and public policy consultants) - partner
- BBC News, Cunningham's Long Good-Bye, October 12, 1999
- Edward Metcalfe, "Jack Cunningham: Nuclear Politician", The Ecologist, Vol 29, Isssue 7, November 30, 1999, Can be accessed via Amazon
- The Guardian, Dr. Jack Cunningham
- Supporters of Nuclear Energy, website
- They Work For You, Jack Cunningham
- Transatlantic Nuclear Energy Forum website
- They Work For You, Jack Cunningham
- Friends of the Earth, Pro-Nuclear Minister Acts To Scupper Wind Farms In Shadow Of Attomic Plant At Sellafield, Press Release, November 16, 1997
- Lord Cunningham of Felling, www.parliament.co.uk accessed 7 November 2012