* House speaker fears it could costs jobs
* Bipartisan measure likely pass in Senate
U.S. House of Representatives Speaker John Boehner on Monday opposed a bill to ban workplace discrimination based on sexual orientation and gender identity, dimming the chances of the White House-backed measure becoming law.
"The speaker believes this legislation will increase frivolous litigation and cost American jobs, especially small business jobs," Boehner's spokesman Michael Steel said in a statement.
Steel issued the statement at about the same time that the bill's backers in the Senate appeared to have gathered enough support to clear a Republican procedural roadblock.
Dean Heller of Nevada became the fifth Senate Republican to announce support for the bill. "This legislation raises the federal standards to match what we have come to expect in Nevada, which is that discrimination must not be tolerated under any circumstance," Heller said.
The bill has become the latest example of the ideological struggle within the Republican party over gay rights. While an increasing number of Republicans are showing more flexibility over gay rights, conservative groups are threatening to mount challenges against those Republicans who support such measures.
The four other Senate Republicans who publicly back the bill are Orrin Hatch of Utah, Susan Collins of Maine, Lisa Murkowski of Alaska and Mark Kirk of Illinois.
These five Republicans, combined with all 53 Senate Democrats and two independents who routinely vote with them, will give supporters of the bill the 60 votes needed in the 100-member Senate to clear a Republican procedural roadblock.
A vote was set for 5:30 p.m. (2230 GMT).
But before the Senate roll call could begin, it was upstaged by the statement from Boehner's office and reaction to it.
House passage had already seemed unlikely, but Boehner's statement underscored the fact that there seems to be no interest from the Republican leadership in even bringing it up.
Regardless, House Democrats said they would push to get a vote on the measure, guardedly hopeful that they could get most members of the chamber to support it.
Fred Sainz, a vice president of the Human Rights Campaign, the largest civil rights group for gays in the United States, ripped into Boehner, saying: "On a day when Senate Republicans are leading and saying 'yes' to employment protections, it doesn't seem very smart for the speaker to say 'no.'"
POLLS SHOW SUPPORT FOR GAY RIGHTS
"He (Boehner) comes across as completely out of step with Americans," said Sainz, alluding to polls showing that most Americans support gays rights.
The bill is seen as the most important gay-rights measure to come before Congress since the 2010 repeal of the U.S. military's "don't ask, don't tell" policy on gays in the armed forces.
Democrats and a number of Republicans have pushed for years for passage of such a bill. In 2007, the then Democratic-led House passed a smaller version of the latest measure, but Republicans in the Senate blocked it.
The current bill would prohibit employers from firing, refusing to hire, or discriminating against those employed or seeking employment, on the basis of their perceived or actual sexual orientation or gender identity.
Such protections are already prohibit discrimination based on race, religion, gender, national origin, age, and disability.
Nearly 90 percent of Fortune 500 companies now extend workplace protections based on sexual orientation and more than a third on the basis of gender identity, said supporters of the bill in the Senate.
Heritage Action, a conservative advocacy group, opposes the bill and last week warned lawmakers that it would include their votes on it in their annual "legislative scorecard."
Heritage Action charges that the measure would undermine civil liberties, increase government interference in the labor market, and trample on religious liberty.
Although the bill exempts religious groups, the U.S. Conference of Catholic Bishops announced its opposition, in part, because of the measure's support for gay marriage, which the Catholic Church opposes.
House rejection of the bill would help shape mid-term congressional elections in November next year when a third of the 100-member Senate and the entire 435-member House will be up for grabs.
The gay community traditionally votes Democratic, and rejection of the bill would probably make it even more likely to maintain that support.
About 5 percent of the voters in the 2012 election were lesbian, gay or bisexual and 76 percent of them voted for Democratic President Barack Obama, according to a poll commissioned by the Human Rights Campaign and conducted by Greenberg Quinlan Rosner Research.
The survey questioned 1,000 voters who participated in the 2012 election. It had a margin of error of plus or minus 3.1 percent.