Democratic presidential candidate and New Mexico Gov. Bill Richardson has tapped into a pipeline of campaign cash from those who lobby government in his home state.

Critics say the contributions raise questions about whether Richardson has used his leverage as governor to help fund his presidential aspirations, and whether his presidential campaign has become another avenue for state lobbyists to curry favor.

Richardson, however, maintains that campaign contributions don't influence him.

"There's no connection between donations and what happens in state government. That's always been an established principle," Richardson said at a recent news conference.

Richardson has collected about $167,000 from lobbyists registered in the state and nearly $403,000 from executives and employees of companies and organizations represented by lobbyists during the first nine months of the year, according to a review of campaign finance reports by The Associated Press.

Richardson also received $22,000 from political action committees affiliated with companies and organizations with lobbyists in New Mexico.

The combined contributions from state lobbyists and their clients account for 3 percent of the $18.5 million in total contributions received by the Richardson campaign through September.

"It clearly has the appearance of a conflict of interest," said Ben Luce of Santa Fe, a clean energy advocate who had a falling out with the Richardson administration this year and has formed a group to fight what he views as undue corporate influence over policymaking in the state.

"There appears to be a pay-to-play situation occurring because people who do make significant donations seem to be the ones getting favors, either contracts or favorable legislation."

Another big source of campaign money has been state workers who have contributed at least $468,000 -- more than any other group of individuals when totaled by their employer.

Richardson also has received at least $89,000 from federal lobbyists and lobbyists from outside of New Mexico, according to the Center for Responsive Politics.

Among the contributions to Richardson:

-- About $30,400 from executives and a state lobbyist for the media and entertainment company, Lionsgate. The state offers tax incentives and interest-free loans for films shot in New Mexico. Lionsgate has done several productions in the state and the company is planning a studio near Albuquerque.

-- Nearly $25,000 from executives, officers and state lobbyists for ValueOptions, which has a contract to manage mental health and substance abuse services for the state. The chairman of the company, Ron Dozoretz, and his wife, Beth, each contributed the maximum amount of $4,600 to Richardson and hosted a fundraiser for him earlier this year. They are friends of Richardson, according to a campaign spokesman. The Virginia-based company won the state contract in 2005 after a competitive bidding process.

-- About $19,700 from executives, lobbyists and a PAC of the state's largest electric utility, Public Service Company of New Mexico. Richardson used one of the utility's lobbyists as an on-loan staffer during this year's legislative session. The lobbyist didn't receive a state salary and remained on the utility's payroll while he worked in the governor's office from mid-November until April. However, the arrangement didn't violate any laws, according to the state's attorney general.

-- About $16,000 came from executives, a state lobbyist and a political action committee affiliated with the GEO Group Inc., which was paid $41 million by the state last year for housing inmates in its privately operated prisons in New Mexico. The state started using the Florida-based company's prisons before Richardson took office. However, another GEO-operated prison is under construction and the state plans to house inmates in it. The Richardson administration contracted with the company in 2005 to manage a long-term care and rehabilitation medical center.

Several presidential candidates have blamed the influence of lobbyists and corporate interests for a lack of progress on health care and other issues in Washington.

Democrat John Edwards has proposed banning contributions by lobbyists to candidates for president and other federal offices.

Richardson said federal financing of elections is the solution.

"I'm going to take lobbyist money and I continue to do that from labor unions, from women's groups, from environmental groups, from nurses," Richardson said. "I think what we need is campaign finance reform."