By Thomas Ferraro

WASHINGTON (Reuters) - The Republican-led House of Representatives passed a bill on Wednesday to renew the 1994 Violence Against Women Act, despite a White House threat to veto it on the grounds that the new version is inadequate and undermines the original law.

Republicans insisted their measure would bolster needed protections to combat domestic abuse. They also accused President Barack Obama and his Democrats of opposing their bill in a bid to rally their liberal base in a presidential election year.

Representative Sandy Adams, one of a number of Republican women sponsors of the measure, said, "We want to make sure that we are not politicizing this issue but just reauthorizing" the law.

On a mostly party-line vote of 222-205, the House approved the bill, which would renew for five years the funding of programs to combat domestic violence and help victims while also toughening penalties. The measure also would increase resources for investigations and prosecutions as well as victims' services.

Obama favors a bipartisan version passed by the Democratic-led Senate last month with the support of all of the chamber's 17 women, 12 of whom are Democrats and five of whom are Republicans.

The Senate bill would provide the same annual $680 million funding level as the House bill but also would expand the law to explicitly include safeguards for gays, lesbians, illegal immigrants and Native Americans.

Democrats said those proposed protections were ignored or inadequately addressed in the House bill. They also said that the House measure would remove some critical protections in existing law.

Democratic Representative John Conyers denounced final changes to the House bill this week as "a fig leaf meant to cover the simple truth" that the measure fails to protect "some of the most vulnerable victims of violence."

The White House, in its veto threat, urged "the House to find common ground with the bipartisan Senate-passed bill and consider and pass legislation that protects all victims."

Republican Representative Virginia Foxx, urged passage of the House bill by saying, "We all want to stop violence against women. We are strengthening the Violence Against Women Act, not weakening it."

GROUNDSWELL OF OPPOSITION

But Democrats said more than 300 groups oppose the Republican bill, including the American Bar Association, the Leadership Conference on Civil Rights, the National Organization of Women, the American Civil Liberties Union and the National Conference of American Indians.

House Democratic Leader Nancy Pelosi said, "Local law enforcement officials have said that this Republican House bill will 'impede criminal investigations, undermine prosecutions and interfere with victim safety.'"

Democrats challenged Republicans to produce a list of organizations that back the bill. Republicans declined to do so.

The Violence Against Women Act, first written by Vice President Joe Biden when he served in the Senate, was reauthorized twice before by Congress with broad bipartisan support.

Yet it ran into trouble this year as women's issues have repeatedly popped up in congressional and presidential campaigns amid a debate over such matters as abortion rights and access to contraceptives.

Democrats and feminist groups have accused Republicans of waging "a war on women" by being insensitive to females on a number of fronts, including pay equity and healthcare.

Republicans deny the charge and accuse critics of trying to divert attention from what they call Obama's mishandling of a struggling economy.

Both sides are jockeying for position to win the vote of women in the November 6 elections. Women voters have long favored Democrats, although they narrowly bucked the trend and went to Republicans in the 2010 congressional election.

A USA Today/Gallup Poll in 12 hotly contested states recently showed that women favor Obama over Republican challenger Mitt Romney, 52 percent to 40 percent, while men back Romney, 50 percent to 42 percent.

(Reporting By Thomas Ferraro; Editing by Bill Trott)