LEXINGTON, Ky. (AP) – Several underfunded candidates have piled on Democratic front-runner Jim Gray for putting his own money into his campaign for a Republican-held U.S. Senate seat.

Six Democratic candidates met in a forum shown statewide on Kentucky Educational Television on Monday night, days ahead of the state’s May 17 primary.

Candidate Ron Leach called the reliance on big campaign fund-raising a “corrosive, cancerous problem.” Candidate Tom Rechtenwald denounced what he called a system of trying to buy votes with campaign ads and mailers. He’s refusing to accept campaign donations.

Gray says his status in the race is due to his experience as a businessman and mayor of Lexington. Gray bolstered his campaignaccount with his $1 million loan to his campaign.

The Democrats are vying to challenge Sen. Rand Paul in November.