A revived push from Virginia Republicans to drug test welfare recipients passed a key hurdle Tuesday in the Senate even as opponents criticized the effort as an attack on the state's poor.

The Senate Finance Committee approved the measure 10-5 along party lines, sending it to the full Senate for what is sure to be a contentious vote. A similar effort passed the Senate last year with Lt. Gov. Bill Bolling casting the deciding vote, but it died in the House after a fiscal analysis found the measure actually would have cost taxpayers between $500,000 and $1.3 million a year, plus initial start-up expenses of $300,000.

A new estimate of the current bill says the state will still likely lose money, but less than $400,000 a year.

The bill requires the 14,500 participants in the state's welfare-to-work program to undergo screening to asses their risk of drug abuse. Those flagged as potential users would then be tested for drugs by the Department of Social Services.

Failing a drug test or refusing to comply would result in a loss of benefits for a year. But they could be reinstated if treatment requirements are met -- a provision Senate Republicans are optimistic makes the bill more likely to pass the General Assembly.

"It's been toned down quite a bit from the original thing. If there's welfare recipients using, we can help them with their addiction," said Sen. Frank Wagner, R-Virginia Beach, who sits on the Finance Committee. "You're hoping welfare payments are going to support families and not to purchase narcotics."

Gov. Bob McDonnell has not taken a position on the measure.

Opponents say drug testing welfare recipients stigmatizes poor people, and similar precautions aren't in place for other public aid, like students who receive college tuition grants or small businesses that get economic assistance.

"Why are Republicans so suspicious of poor people? It begs the question," said Sen. Louise Lucas, D-Portsmouth. "This is insulting. The fact is, very few of those who qualify for temporary public assistance use illegal drugs."

According to a Department of Social Services presentation from December, most studies show only a slightly higher drug-use rate among welfare recipients compared with the general population.

There may be constitutional issues, as well, said Claire Gastanaga, executive director for the ACLU of Virginia, because it singles out a particular class of people.

"It's a solution in search of a problem," Gastanaga said.

Florida passed a drug-testing measure in 2011, but it was later suspended by the courts. Before it was knocked down for constitutional concerns, officials found only 2 percent of welfare recipients tested positive for drugs.

Michigan started testing welfare beneficiaries in 1999, but the courts found that unconstitutional. In recent years, Arizona and Missouri began testing suspected users in measure similar to the one pending in the Virginia General Assembly.