FreedomWorks, a deep-pocketed Tea Party group, will throw its support behind Evan Feinberg in his primary challenge to Rep. Tim Murphy (R-Pa.).

The group sent out a press release that it will "make an important announcement regarding the Pennsylvania District 18 congressional race" on Tuesday and a source confirmed that it will back Feinberg, a young former staffer of Sens. Tom Coburn (R-Okla.) and Rand Paul (R-Ky.).

Feinberg has so far struggled in fundraising, bringing in only $50,000 in the last quarter. But conservative outside groups seem ready to try and make an example out of Murphy, something FreedomWorks's planned announcement indicates.

Murphy has already been a target of the Club for Growth, who attacked him in television ads. Both Paul and Coburn hinted to The Hill in December that both could endorse their former staffer.

Murphy has a generally conservative record but has been more centrist on some economic issues. He voted for expanding the State Children's Health Care plan and for bailing out mortgage giants Fannie Mae and Freddie Mac.