Republican U.S. Sen. Susan Collins holds a significant lead over her Democratic challenger, U.S. Rep. Tom Allen, in two new polls released today.

A poll by Pan Atlantic SMS Group found that Collins had 57 percent of the vote, Allen had 36 percent and 7 percent were undecided.

And a poll by SurveyUSA gave Collins 54 percent of the vote and Allen 43 percent, with 3 percent undecided.

Barack Obama, the Democratic presidential nominee, leads Republican John McCain in the Pan Atlantic poll, 51 percent to 39 percent, with 10 percent favoring other candidates or undecided.

The SurveyUSA poll showed Obama with a 15-percentage-point lead over McCain, 54 percent to 39 percent, with about 6 percent undecided or supporting other candidates.

Pan Atlantic said the results were based on computer-assisted telephone interviews conducted Oct. 13-16 with 400 registered Maine voters who said they were likely to cast ballots on Nov. 4.

The poll has a margin of error of plus or minus 4.9 percent at a 95 percent confidence level for the presidential and Senate races.

A much tighter race is reported in the 1st Congressional District, where Democrat Chellie Pingree and Republican Charlie Summers are competing for the seat now held by Allen.

The poll found that Pingree had 43 percent of the vote, Summers 32 percent - and 25 percent are still undecided.

Because of a smaller sample size, however, the results in the 1st District race have a higher margin of error, 6.8 percent at a 95 confidence level.

On referendum Question 1, which would repeal a new tax on beer and soda to fund the Dirigo Health insurance program, 57 percent would vote to eliminate the tax and 35 percent would keep it, with 8 percent undecided.

Question 2, to allow a casino in Oxford County, would be headed for defeat, with 40 percent in favor, 52 percent opposed and 8 percent undecided, the poll found.

SurveyUSA's poll, conducted for WCHS-TV and WLBZ-TV, was based on computerized telephone interviews with 642 likely voters on Sunday and Monday.

It has a margin of error of 3.9 percent, with a 95 percent confidence level.