More than a dozen Virginia legislators are flying to France this month on all-expenses paid trips as part of an aggressive lobbying effort by a company pushing lawmakers to lift a ban on uranium mining in the state.

Virginia Uranium invited nearly all 140 state lawmakers to France as it looks to mine what is thought to be the largest deposit of uranium in the United States, in south central Virginia, despite concerns about unearthed radioactive material that could contaminate the area’s land, air and drinking water.

Five legislators arrived in Paris on Wednesday to see a closed mine in Bessines, in western France, where uranium was excavated for 50 years until the late 1990s. Nine others leave Tuesday on a five-day trip — expected to cost $10,000 a person — that includes about three free days in Paris.

“I want to learn as much as possible so I can make an intelligent decision,” Del. Jeion A. Ward (D-Hampton) said. “My vote can’t be bought. I’m going and coming right back. I’m not going to the south of France. But if anyone else wants to, there’s nothing wrong with that.”

The trips are permissible under Virginia law and must be reported to the state as gifts next year. Most legislators declined the pricey jaunt — the second invite from the company in two years — months before the fall election.

Del. David B. Albo (R-Fairfax) said he declined the trip because of how it might be perceived in what might be a tough reelection bid. Every General Assembly seat is up for grabs.

“I thought it would be a useful trip knowledge-wise, but politically speaking, I think it has the appearance of impropriety,” Albo said.

Two uranium deposits were found three decades ago in Coles Hill, near Chatham, a small town in Pittsylvania County. They begin at the ground’s surface, under land used to raise cattle, hay and timber, and run about 1,500 feet deep.

The company said tests indicate that about 119 million pounds of uranium — worth as much as $10 billion — are below the surface. That would be enough to supply all the country’s nuclear power plants for about two years or all of Virginia’s demands for 75 years.

Virginia Uranium hopes to persuade the General Assembly to repeal the nearly three-decade ban on mining at its regular session in January by convincing lawmakers that mining can be done safely. The trip to France is designed to help show that mining was done safely and the region remains free of radiation.

“This is not a vacation. There may be some free time, but going across the pond in three days is not a cakewalk,” said Patrick Wales, the company’s project manager. “If we’re going to ask our legislators to make a decision, it’s important to have the best information in front of them.”

Sens. Mamie E. Locke (D-Hampton) and L. Louise Lucas (D-Portsmouth) and Dels. William R. Janis (R-Goochland), John A. Cosgrove (R-Chesapeake) and Mamye E. BaCote (D-Newport News) left Tuesday and will return Sunday, according to legislative offices and a source close to the lawmakers who was not authorized to speak for them.

Patrick Wales, a project manager with Virginia Uranium, shows an exploration drill hole created in 2008 at Coles Hill Farm about six miles east of Chatham. (Tracy A. Woodward/THE WASHINGTON POST)

Locke, reached in Paris on Wednesday, said she was inclined to vote against mining but wanted to see the mine for herself. “Let me try to do this with an open mind,” she said. “There are a lot of questions we have to answer.”

Dels. David L. Englin (D-Alexandria), Barry D. Knight (R-Virginia Beach), L. Scott Lingamfelter (R-Prince William), James P. Massie III (R-Henrico), Kenneth R. Plum (D-Fairfax), Lionell Spruill Sr. (D-Chesapeake) and Roslyn Tyler (D-Greensville) will leave Tuesday and return June 26.

Del. Mark D. Sickles (D-Fairfax) said he is leaving this weekend to go sightseeing in Paris and will join the group Thursday for the day but is paying his own airfare and lodging. “It could appear to be extravagant,” he said.

Most other legislators did not return calls for comment Wednesday and Thursday.

Uranium has never been mined in Virginia, confined instead in the United States to drier, less populated areas such as Utah, New Mexico, Wyoming and Nebraska, according to the U.S. Nuclear Regulatory Commission. Uranium mining is more common in Canada, Australia, Eastern Europe and Africa.

Virginia Uranium officials said they are taking legislators to France because the former uranium site in Bessines is so similar to the one in Pittsylvania County in terms of rainfall levels, population density and agricultural production.

“One of the things we consistently hear is that uranium has not been mined anywhere like Pittsylvania County,” Wales said. “There is no better example [than Bessines]. There are a lot of similarities.”

Since 2007, when Virginia Uranium was incorporated, the company has spent hundreds of thousands of dollars lobbying the General Assembly. It has donated $55,150 to candidates in Virginia since 2008 and retained four of Richmond’s most influential lobbying firms, as well as a top public relations firm.

“It’s always troubling when one company spends so much money directly lobbying the legislators who will decide its fate,” said Cale Jaffe, a senior attorney for the Southern Environmental Law Center, which opposes mining.

International travel is not terribly common for state legislators in Virginia, according to financial disclosure forms posted by the Virginia Public Access Project, a nonpartisan tracker of money in politics.

Last year, 11 lawmakers visited Turkey as guests of the American Turkish Friendship Association. Three others went to Taiwan on trips funded by Taipei’s economic development office and a young political leaders program. Lobbyists and corporations paid for a few domestic trips for senators and delegates.

Virginia Uranium paid for a trio of legislators — Sens. John C. Watkins (R-Chesterfield) and Frank W. Wagner (R-Virginia Beach) and Del. Onzlee Ware (D-Roanoke) — to go to France last year at an individual cost of $8,500 to $9,500.

Wagner, who said the trip was beneficial but hasn’t made up his mind whether he supports uranium mining, also flew to Saskatchewan, Canada, last week — paid for by Virginia Uranium — to see an active mine. “My hope is other legislators take advantage,” he said.

Environmental groups, including the Piedmont Environmental Council and the Southern Environmental Law Center, said uranium should not be mined in Virginia’s highly populated areas and relatively rainy climate. They said they are worried that radioactive materials could contaminate natural resources, cause cancer or other illnesses, and have long-term effects on plants and animals. The Coles Hill area supplies drinking water locally and to parts of Hampton Roads and North Carolina.

Company officials said that safeguards have been put in place since mining at Coles Hill was first considered and that the federal government regulates mines and mills with regard to safety and homeland security. Uranium would be mined underground.

The state’s Coal and Energy Commission asked the National Academy of Sciences and the Virginia Center for Coal and Energy Research at Virginia Tech to review whether the uranium can be safely mined.

Gov. Robert F. McDonnell said this week that uranium should be mined if the study shows it can be done.

“If we can do it safely, we ought to do it,” McDonnell (R) said. “If we can’t, then we ought to have another policy. I don’t see how we move forward without good science.”

Staff writer Rosalind S. Helderman and researcher Magda Jean-Louis contributed to this report.