WASHINGTON (Reuters) - Republican U.S. Senator Saxby Chambliss of Georgia will not run for a third term in 2014, a congressional aide said on Friday, potentially leaving Congress with one less Republican who was willing to sit down with Democrats on fiscal issues.

Chambliss, who rebelled against anti-tax lobbyist Grover Norquist by saying he was open to raising taxes, was being targeted by conservative Tea Party members in Georgia.

No one had announced a challenge to Chambliss.

Chambliss is a member of the so-called Gang of Eight group of senators, a bipartisan alliance working for deficit reduction.

(Reporting By Rachelle Younglai; Editing by Vicki Allen)