WILMINGTON, Ohio - Sen. John McCain vowed Thursday to call for a congressional hearing and Justice Department review into the potential loss of about 8,000 jobs in this Ohio town as his presidential campaign once again faced questions about its ties to lobbyists.

McCain's promise of action on plans by DHL Express to move its shipping operations away from an air park here came at an emotional meeting with workers.

It also came after a Democratic effort to highlight McCain's role in a congressional deal that brought DHL to Wilmington in the first place, and the former work of his campaign manager, Rick Davis. Davis, then a lobbyist for DHL and its German owner, Deutsche Post World Net, helped persuade Congress to accept the 2003 merger.

Mindful of the state's place on the electoral map -- it gave President Bush the electoral votes needed for reelection in 2004. And it gave McCain the chance to demonstrate empathy about the economy, when he told about two dozen workers and civic leaders he would do everything possible to stop the job losses.

"I can't assure you that this train wreck isn't going to happen, but I will do everything in my power to see that we avert it," he said.

Mary Houghtaling, who questioned McCain about the issue last month, said: "My straight talk would be, 'Please don't let this foreign company ruin our part of the world.' "

The issue has special resonance because of Davis' involvement and McCain's. McCain, as chairman of the Senate Commerce Committee, urged Sen. Ted Stevens to abandon proposed legislation that would have prohibited foreign-owned carriers from flying U.S. military equipment or troops, which Airborne Express said was aimed at torpedoing its merger with DHL. McCain opposed the bill, spokesman Brian Rogers said, because it could have hurt the military's airlift capabilities in a time of war.

Also, McCain's campaign said it is returning $50,000 in contributions solicited by a foreign citizen. The move follows the disclosure that the money was being raised by Mustafa Abu Naba'a, a citizen of Jordan and the Dominican Republic, who is a business partner of Florida Republican Harry Sargeant III.

The New York Times reported that Sargeant, who has collected hundreds of thousands of dollars for McCain, allowed Abu Naba'a to bring in about $50,000 in donations in March from a family in California, the Abdullahs, and their friends.

The Abdullahs and other Arab-Americans in California also contributed tens of thousands of dollars to Democrat Hillary Rodham Clinton and Republicans Rudolph Giuliani and Florida Gov. Charlie Crist.

It is illegal for foreigners to contribute to U.S. political campaigns. McCain's campaign said Abu Naba'a did not do so but that some of the people solicited had no intention of supporting McCain for president.

The Washington Post and AP contributed to this report.