Vincent Cable began his political life with Labour, leaving when the party lurched leftwards in the early 1980s to join the SDP.
Regarded as a highly able, he had been an adviser to John Smith when the future Labour leader was trade secretary in the Callaghan administration.
Mr Cable has pursued a successful career outside politics and his former employers include Shell International, where he was chief economist.
He is the author of numerous pamphlets and books.
The Twickenham MP first won his seat in 1997 after running for Parliament at every previous election since 1983. Before covering his current frontbench brief he was trade and industry spokesman.
He was a key supporter of Sir Menzies Campbell's successful party leadership campaign.