Sen. Russ Feingold's (D-Wis.) main Republican competition is running neck-and-neck with him, according to a new poll.

A new Rasmussen Reports telephone survey of likely voters shows Feingold with 46 percent support to businessman Ron Johnson’s 44 percent.

Johnson was endorsed at last weekend's state GOP convention.

Republicans will formally pick their nominee in the Sept. 14th primary, but Johnson is expected to get the nomination.

In its analysis of the race, Rasmussen notes that Feingold continues to fall short of 50 percent regardless of the Republican he's matched up against.

Feingold's campaign released a statement on the poll.

"It's time for the media to move beyond our opponents slogans, junk polls, who's in and who out, and start covering the issues that matter to the people of Wisconsin," said Trevor Miller, a spokesman for Feingold's campaign.

-- This post was updated at 1:50 p.m.