A computer expert, Mr Jones has been an active, if not flamboyant, MP for the Gloucestershire town.
As the Liberal Democrats' science and technology spokesman, one of the MP's most high-profile campaigns was over the millennium bug.
Mr Jones, 51, entered Parliament in 1992, wresting the Cheltenham seat from the Tories.
He benefited at the time from a split in the local Tory Association, some of whose members felt that Conservative Central Office had imposed a token black candidate on them - John Taylor (now Lord Taylor) a successful barrister.
Mr Jones had earlier unsuccessfully fought the seat in 1979. At the last election he increased his 1992 majority of 1,668 to 6,645.
Mortgage campaign
In 1994, the MP accused Gloucestershire social services of making a mistake in paying a young offender's parents £60 a week "pocket money" to spend on outings in an attempt to prevent him from committing further crimes.
And two years later he warned that bootleggers were threatening to fire-bomb pubs to force landlords to buy cheap, smuggled beer.
He called on the then Chancellor, Kenneth Clarke, to harmonise duty levels throughout the EU in a bid to stop the racket.
Soon after his election to Westminster he issued a party document committing the Liberal Democrats to replacing mortgage interest tax relief for future home buyers with a housing subsidy.
He has been described as a computer consultant "with a charisma to match, and a flat, classless way of speaking".
Mr Jones was educated at Prince Henry's Grammar School, Evesham.
Since 1992 he has been the Liberal Democrat spokesman, at various times, on England, local government, housing, science and technology and consumer affairs.
After the last election he was appointed spokesman on culture, media and sport. He is married with one son and twin daughters.
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