Updated

By: Chad Pergram and Steve Brown, FOX News

FOXWIRE: FOX has learned that eight-term Rep. Mark Souder (R-IN) will announce his resignation today after it came to light that he was conducting an affair with a female staffer who worked in his district office.

Multiple senior House sources indicated that the extent of the affair would have landed Souder before the House Ethics Committee.

Elected as a family values conservative as part of the Republican revolution in 1994, Souder survived a tough re-election challenge in 2008 and survived a contested primary two weeks ago.

Souder was absent from Washington most of last week, missing multiple votes and only voting on Thursday.

Souder's resignation would make him the second lawmaker to step down in less than two months. In March, former Rep. Eric Massa (D-NY) resigned amid allegations that he sexually harassed male staffers. Massa's case is now before the House Ethics Committee.