Conservative groups are sending in reinforcements to boost Republican Jim Tedisco in the special House election in New York’s 20th district.

The U.S. Chamber of Commerce on Tuesday announced that it was endorsing Tedisco, the state Assembly Minority Leader who is battling venture capitalist Scott Murphy (D) in the March 31 contest.

“James Tedisco is a champion for the people of New York and an invaluable leader on important business issues,— Bill Miller, the chamber’s senior vice president and political director, said in a statement. “The Chamber believes he will be an effective legislator and supporter of businesses of every size if elected.—

Meanwhile, a fairly new conservative political action committee, Our Country Deserves Better Committee PAC, announced that it would begin airing TV and radio ads in the district beginning this weekend. According to the group, the ad buy in the Albany and New York City media markets “is expected to reach well into the hundreds of thousands [of dollars] by Election Day.—

Our Country Deserves better is a PAC that was started in recent months by several well-connected Republican operatives and former elected officials in California. The group has previously aired ads across the country criticizing President Barack Obama and defending Alaska Gov. Sarah Palin (R). The group will preview its New York ads on its Web site Thursday.

The 20th district seat, which became vacant in late January when then-Rep. Kirsten Gillibrand (D) was appointed to the Senate, represents a major pick-up opportunity for Republicans. But Murphy has been boosted in recent days by news that he has been endorsed by the New York AFL-CIO and that he will appear on the ballot as the nominee of the centrist Independence Party. Murphy is due to be in Washington, D.C., for a fundraiser with Congressional leaders on Wednesday.