Senator Tom Harkin, a veteran Iowa Democrat and one of the most liberal senators, said on Saturday, Jan 26 he will not seek re-election in 2014, putting at risk what was considered a safe Democratic seat.

Harkin, 73, who has focused much of his nearly 40-year congressional career on farm policy, education and expanding rights for people with disabilities, is the third senator facing re-election next year who has announced his retirement, following Democrat Jay Rockefeller of West Virginia and Republican Saxby Chambliss of Georgia.

"It's somebody else's turn. It's time for me to step aside ... . I think that's not only good for our party, it's good for our state and for our nation," Harkin said in an interview with Reuters.

He said he had no health problems but had promised his wife that he would quit before it was too late to enjoy other things in life.

In remarks to the Iowa Democratic Party central committee after his announcement, Harkin said he would stay politically active, Reuters reported.