Biggest FTSE directorship: non-executive chairman, National Grid (utilities, £406,000).

Other FTSE directorships: non-executive chairman, P&O (transport, c£33,000); non-executive director, Carnival (leisure, £64,000).

Power 100 score: 326

Age: 63

Career: Sir John Parker’s career has three strands — engineering, energy and shipping. As a shipping engineer, he worked for Harland & Wolff, the shipbuilder, from 1963 to 1989. He was also chairman and chief executive of Babcock from 1993 to 2000 and a non-executive director of GKN from 1993 to 2002. He continued in the same role at Brambles, which swapped assets with GKN in 2002, until 2003. He was Firth Rixson’s deputy chairman from 1999 to 2001 and chairman from 2001 to 2003. In energy, Parker was a non-executive director of British Coal from 1986 to 1993. From 1997 to 1999 he was a non-executive director of BG, the British Gas successor. When BG hived off Lattice, its transmission business, in 2000, Parker was made non-executive chairman and when Lattice merged with National Grid in 2002 he became chairman of the merged group. Back in shipping, Parker joined the board of P&O Princess Cruises as a non-executive director when it demerged from P&O in 2000. When Princess was bought by Carnival in 2003 he continued as a director of Carnival. He succeeded Lord Sterling of Plaistow as chairman of P&O, the port operator, this year. From 2002 to 2005, he chaired RMC, the building products company.