Freshman Rep. Eric Massa (D-N.Y.) is expected to announce on a 3:30 p.m. conference call that he will not run for a second term in November.
A source who has spoken to Massa said the Congressman will announce he is leaving because of a recurrence of cancer. Massas retirement was first reported by the New York Daily News on Wednesday afternoon.
Massa was first elected in 2008, when he defeated then-Rep. Randy Kuhl in the Republican-leaning 29th district.
Republicans had been targeting Massa for defeat in November, and the race to succeed him will likely be competitive.
He will become the 15th Democrat to announce plans to leave the House at the end of this year.
Rep. Elijah Cummings, D-Md., right, hugs Harold Schaitberger, General President of the International Association of Fire Fighters, after the Congressman spoke at the IAFF's Legislative Conference General Session at the Hyatt Regency on Capitol Hill, March 9, 2015. The day featured addresses by members of Congress and Vice President Joe Biden.