Wealthy third-party candidate Jack Davis unveiled the endorsement of tea party darling David Bellavia on Wednesday, a move intended to counter charges by conservative groups that Davis is largely a tea party impostor in western New York’s looming special election.

“Jack Davis is honored to have the support of David Bellavia, a man of integrity and honor. And it will certainly add momentum to Jack Davis’ campaign, which is picking up more support every day,” Davis spokesman Curtis Ellis told Roll Call on Wednesday. “He’s not just endorsing Jack, he’s actively campaigning for Jack.”

The endorsement comes 13 days before Election Day. It will be formally announced during a 6 p.m. event with veterans, a setting aimed at tempering a conflict between the two men dating back to a 2006 campaign ad, in which Bellavia accused Davis of playing politics with troops.

“Veterans in Western New York and voters of all stripes have one clear choice for Congress, and that is Jack Davis, a true independent who will work for the people as he caucuses with the Republicans in the House of Representatives,” Bellavia said in a statement.

An Iraq war veteran and author, Bellavia was the sentimental favorite of western New York tea party groups in the days and weeks after Jane Corwin claimed the GOP nomination earlier in the spring. With the help of tea party activists, Bellavia collected thousands of signatures to try to qualify for the May 24 ballot, but he ultimately backed off the effort after a paperwork blunder.

Davis became the only one to qualify for the ballot by collecting signatures and will appear on the Tea Party line. A $650,000 television advertising blitz from the outside conservative group American Crossroads began airing Wednesday and notes that Davis previously ran for Congress as a Democrat.

“This time, Jack’s pretending to be conservative,” the Crossroads ad says. “You can’t trust Jack.”

Davis has become the focus of attacks from the right, which are largely ignoring Democrat Kathy Hochul. The Democrat held a narrow lead over Corwin in a poll released earlier in the week, but the lead is largely attributed to the presence of Davis, who has vowed to spend $3 million on the election and is draining support from Corwin.

Groups on the right believe they can save Corwin in the conservative district by hurting Davis. As further proof, the National Republican Congressional Committee released a Web video late Tuesday that links Davis to President Barack Obama and House Minority Leader Nancy Pelosi (D-Calif.).

“The most important thing voters should know about Jack Davis is that he is a Democrat,” NRCC Communications Director Paul Lindsay said. “He’s attempting to fool western New York, but it’s clear that Democrat Jack Davis is a true Nancy Pelosi liberal.”

Bellavia’s endorsement, however, runs contrary to attacks by the NRCC and Crossroads, an organization with ties to GOP strategist Karl Rove created during the 2010 cycle to help elect Republicans.

“Jack is talking to the people of this district, that’s who matters. Outside agitators are not needed here,” Ellis said. “The money and their spending works against them. Karl Rove is a bigger enemy of the tea party than King George.”