Rep. Peter King (R-N.Y.) ruled out, for the second time, a challenge to Sen. Kirsten Gillibrand (D-N.Y.).

King, who announced in September he would not run for the Senate, had been again entertaining the notion in recent weeks, in the wake of former New York City Mayor Rudy Giuliani’s confirmation that he would not run. But in a statement released Monday, King said, “While the political situation has changed dramatically in the Republicans’ favor since September and I believe that Sen. Gillibrand can and will be defeated in 2010, I will not be a candidate for the Senate.”

King said he based his decision on ” two main reasons.” The first is the time a Senate campaign would take away from his duties in the House.