LONDON (AFP) - Diane James quit as head of the eurosceptic UK Independence Party on Tuesday (Oct 4) just 18 days after being elected to replace Nigel Farage, according to senior party sources quoted by British media.

James was elected leader on Sept 16 after Farage - one of the best-known faces of the "Brexit" campaign - quit following Britain's shock vote to leave the EU, saying his life's ambition had been achieved.

The Press Association, Sky News and The Telegraph newspaper quoted senior party sources as saying she had resigned, with reports suggesting she had decided to step down due to her husband's ill health.

A UKIP spokesman was not immediately available to comment on the reports.

James, 56, previously served as the party's home affairs spokeswoman and is a former pharmaceutical industry executive. She is a member of the European Parliament.

Ahead of her election as UKIP leader a September poll by YouGov found just 8 per cent of respondents knew who she was.

James' departure raises the prospect that Farage could make a comeback, although he has ruled out such a move.

"Not for 10 million dollars," he told the Press Association.

Another possible replacement could be Steven Woolfe, an MEP who had been the favourite in the race but was controversially barred from the leadership battle for submitting his application 17 minutes late. He blamed computer problems for the delay.

Speaking following the decision in August, Woolfe said he was "extremely disappointed" and branded UKIP's ruling National Executive Committee (NEC) "not fit for purpose".

Three members of the NEC resigned in protest at the exclusion of Woolfe.

Since UKIP was co-founded by Farage in 1993 its has grown into Britain's third biggest party by the number of votes cast at last year's general election.

The anti-EU party won 12.6 per cent of the vote in the 2015 election, though it only has one MP to show for it under Britain's first-past-the-post system.