MANCHESTER, N.H. — Democratic Sen. Jeanne Shaheen and her GOP rival Scott Brown are running neck-and-neck on the eve of Election Day, according to two new polls released Sunday night in New Hampshire.

A WMUR Granite State Poll poll by the University of New Hampshire Survey Center has Shaheen leading Brown 46 percent to 43 percent among likely voters. When the survey takes into account which candidate undecided voters are leaning towards, Shaheen takes 47 percent support to Brown's 45 percent.

Polling in the state has been volatile in recent weeks, frequently showing Shaheen in the lead but nonetheless yielding results that fall within the margin of error. A WMUR Granite State poll released Thursday had Shaheen leading Brown 47 percent to 39 percent among likely voters. That larger lead now appears to have eroded.

Another poll released Sunday night by New England College also shows an extremely close race. In that automated poll, the two candidates each take 48 percent support.

The New Hampshire Senate race is one of the most closely watched elections in the country. Shaheen has been widely considered among the most likely Democratic incumbents to keep her seat in Washington but, taken together, the two new polls appear to indicate the race is a toss-up. Republicans are eager to flip the seat in their favor as part of their effort to win control of the Senate.

The two campaigns have insisted that the election will come down to the strength of their get-out-the-vote operations. The candidates have spent the weekend crossing the state to meet with voters and canvassers.

The WMUR poll surveyed 757 likely voters by cell phone and landline between Oct. 29 and Nov. 2. The poll's margin of error is plus or minus 3.6 percentage points. The New England College automated poll surveyed 1,526 likely voters between Oct. 31 and Nov. 1. The margin of error for the poll is plus or minus 2.5 percentage points.