Connecticut’s Senator Lieberman, who’s running for re-election as an independent, is in a statistical tie with Democratic primary winner Ned Lamont, according to a poll taken by the American Research Group Inc.in the past five days.

The telephone survey of 790 likely voters in Connecticut found that 44% would vote for Mr. Lieberman if the election were held today compared with 42% for Mr. Lamont. The Republican challenger Alan Schlesinger drew 3% of the vote. The margin of error is plus or minus 3.5 percentage points.

The August 17-21 poll included interviews after Mr. Lieberman defended his support for the Iraq war on CBS’s “Face the Nation” Sunday talk show. An August 10-14 Quinnipiac University poll had put Mr. Lieberman ahead of Mr. Lamont by 12 points.

“It looks better for Lamont as the turnout grows because there is an antiincumbent feeling,” said Dick Bennett, president of the Manchester, New Hampshire-based American Research Group. “If this were a lower-interest race, I would say Lieberman would have it.”

The independent American Research Group poll found that Mr. Lieberman had an edge of 10 points over Mr. Lamont among unaffiliated voters and drew 57% of the registered Republicans, compared with 18% for Mr. Lamont and 11% for Mr. Schlesinger. Democrats backed Mr. Lamont 65% to 30%.

Among the 600 participants who said they always vote, Mr. Lieberman drew 47%support to Mr. Lamont’s 43%. That was within the four-point margin of error for that subgroup.

The earlier Quinnipiac poll included 1,319 likely voters in Connecticut and had a margin of error of 2.7 percentage points. Mr. Bennett said the two polling groups may use different criteria for identifying voters most likely to go to the polls.

Mr. Lamont won the state’s Democratic Senate primary August 8 with 52% of the vote to Mr. Lieberman’s 48%. Within hours, Mr. Lieberman filed to run as an independent in the general election.