WASHINGTON - National Republican Senatorial Committee Chairman John Ensign (R-Nev.) wants to make it absolutely clear: national Republicans are in Colorado's Senate race for good.

"The Colorado race has closed up, and that's the reason we're going to stay there. We're going to stay there up until the end," Ensign told an audience at a National Press Club breakfast Tuesday morning.

Pointing to internal polling figures showing Republican candidate Bob Schaffer five points down, Ensign said, "Basically, that's a very winnable race. It's a battleground in the presidential race and we're going to be there until the end."

Ensign's comments came just days after the NRSC disputed media reports saying the committee was prepared to pull out of the race. Citing unnamed Republican officials in Washington and Colorado, The Atlantic Online reported on Friday that the committee had decided to pull its advertising in the state.

But the NRSC and Schaffer's campaign disputed the report, saying the committee was maintaining its investment in the race. Later that day, the NRSC unveiled a 30-second advertisement charging that Democratic candidate Mark Udall "is not honest about his past. And now it's catching up with him."

Public polling has shown Udall moving ahead of Schaffer. Schaffer's campaign is out with an internal survey showing Udall five points ahead while Udall's campaign released a poll showing Udall maintaining a 12-point lead.

Nonetheless, Ensign heaped praise on Schaffer, calling the former congressman "an outstanding candidate." Ensign also acknowledged the difficulties for Republicans running in Colorado, a state that is trending Democratic.

"Whoever runs was going to have a tough time in Colorado. It's a tough state. It's a tossup state," he said.

Ensign's counterpart, Democratic Senatorial Campaign Committee Chairman Chuck Schumer, also on hand for the breakfast, expressed confidence the race was breaking in Udall's favor.

"Our analysis is that Mark Udall has pulled way ahead," said Schumer.