In a new poll released by Public Policy Polling (PPP) today, Republican candidate Mark Kirk has pulled ahead of Democrat Alexi Giannoulias in the U.S. Senate race. Below are the results, with the findings of a January 2010 PPP poll in parentheses:

Giannoulias: 33% (42%)
Kirk: 37% (34%)

Polls conducted since the February 2 primary by both Research 2000 and Rasmussen showed Giannoulias leading. Research 2000 gave him a 43-36 advantage while Rasmussen showed him ahead 44-41.

The latest PPP survey suggests Giannoulias may be losing some support among his own party's rank-and-file, attracting only 54 percent of the Democratic respondents.  By contrast, almost 80 percent of Republicans surveyed backed Kirk.

UPDATE (1:30 p.m., 6/29/2010): The DailyKos, who commissioned a poll mentioned in this article, has renounced all of their polling conducted through Research 2000.