National Republicans are again hammering Rep. Tim BishopTimothy (Tim) Howard BishopDems separated by 29 votes in NY House primary Flint residents hire first K Street firm House moves to vote on .1T package; backup plan in place MORE (D-N.Y.) for being the subject of a congressional ethics investigation with a new television ad.

The ad, from the National Republican Congressional Committee, points to an investigation into whether the congressman’s office solicited a campaign contribution in exchange for securing permits for a constituent.

“Bishop did the favor, then got the cash,” a narrator says in the ad.

The narrator goes on: “Corruption, federal investigations. Tim Bishop is everything that’s wrong with Washington.”

A report out prior to the 2012 general elections revealed Bishop helped get environmental permits for a constituent hoping to launch fireworks at a birthday celebration. Before those permits were secured, however, Bishop’s aides allegedly reached out to the constituent and requested a campaign contribution.

Though Bishop has denied any wrongdoing and the constituent himself has called the issue a “nonstory,” the Ethics Committee is still reviewing the situation, and the FBI collected information on the case late last year.

Republicans believe the ongoing investigations have made Bishop, a perennial GOP target, the most vulnerable he’s ever been, and the NRCC has attacked him on the investigation in ads before.

Republicans George Demos, a former prosecutor with the U.S. Securities and Exchange Commission; and state Sen. Lee Zeldin are vying for the opportunity to take him on in the general election.