Oct 19 (Reuters) - Democratic presidential candidate Jim Webb is considering an independent bid for the White House, and will hold a news conference about his candidacy on Tuesday, his campaign said on Monday.

Webb, a former U.S. senator from Virginia, has lagged behind front-runner Hillary Clinton and her chief rival, U.S. Senator Bernie Sanders of Vermont, in opinion polls, along with former Maryland Governor Martin O'Malley and former Rhode Island Governor Lincoln Chafee.