By Thomas Ferraro and Richard Cowan
WASHINGTON, Feb 7 (Reuters) - Top Democrats in the U.S. House of Representatives unveiled a broad proposal on Thursday to curb gun violence that mirrors the one offered last month by President Barack Obama, including a ban on semi-automatic assault weapons.
But it remained unclear if the proposals will be put to a vote. The House Republican leadership has said it doesn't intend to bring legislation to the floor until the Senate has acted, and there are doubts the Senate will pass gun control legislation.
"We know it's going to be tough, but we also know this is important," said Mike Thompson, chairman of the 12-member House Democratic Gun Violence Prevention Task that drafted the proposals.
Opponents led by influential and well-financed pro-gun groups charge that new restrictions on firearms would violate the right to bear arms.
Backers disagree. They argue that while Americans have the right to own guns, the government has the responsibility to impose restrictions for the public good.
There has been unprecedented public support for tougher gun laws in wake of the Connecticut school massacre in December that killed 20 children and six adults.
In addition to outlawing semi-automatic assault weapons and imposing limits on high-capacity ammunition clips, the House Democrat package, like one advanced by the White House, would require that all gun buyers be subject to background checks and provide for improvements in mental health services.
At this point the only gun-related proposal with much bipartisan support is the one requiring universal background checks.
The new package was announced on the second day of a three-day retreat by House Democrats that featured a visit by the president. He suggested that despite opposition by gun groups, many individual gun owners favor new restrictions.
"A majority of responsible gun owners recognize that we can't have a situation in which 20 more of our children or 100 more of our children or 1,000 more of our children are shot and killed," Obama told the meeting.
"There are common sense steps we can take," Obama said, "and we should not shy away from taking those steps."
Vice President Joe Biden, who led the effort to craft the White House proposals, told House Democrats on Wednesday that they have an obligation to step up and take action.
"I don't want to hear about 'Well, we can't take it on because it's too politically dangerous,'" Biden said. "There's an overwhelming consensus about the need to act."
Biden acknowledged that members of Congress who backed a 1994 ban on assault weapons - which expired in 2004 - faced a voter backlash that may have cost many of them their jobs.
"I'm here to tell you the world has changed since 1994," Biden said.
A bipartisan group of senators on Thursday offered legislation expanding access to mental health professionals and improving the quality of mental health care in the United States.
The group, led by Democratic Senator Debbie Stabenow of Michigan and Republican Senator Roy Blunt of Missouri, noted that people experiencing severe but undiagnosed psychological disorders are at risk of committing violent acts at a rate 15 times higher than those receiving treatment.
The powerful National Rifle Association has led the charge against stricter gun laws but has agreed with those who have called for improvements in mental health treatment.
It strongly condemned the Democratic proposals on Thursday. "Congress should instead focus its energies on the things that will actually keep our families and communities safer - prosecuting criminals who misuse firearms; securing our schools; and fixing the broken mental health system that keeps dangerously ill people on the street," the group said.