MANCHESTER, N.H. -- Democrats Al Gore and Republican John McCain held solid leads on the eve of New Hampshire's first-in-the-nation presidential primary, a Reuters-WHDH tracking poll found Monday.

The two-day poll consisted of interviews with 817 likely Democratic voters and 812 likely Republican voters, conducted half on Sunday and half on Monday. The interviews ended less than 12 hours before the polls opened.

In the Republican race, Arizona Sen. John McCain moved into a 10-percentage-point lead over Texas Gov. George W. Bush and led 41-31 percent.

The other three Republicans trailed far behind. Publisher Steve Forbes polled 13 percent, talk radio host Alan Keyes had 8 percent and conservative activist Gary Bauer had 1 percent with the rest undecided. The statistical margin of error was plus or minus 3.6 percentage points.

Among Democrats, Vice President Al Gore led former Sen. Bill Bradley 52-40 percent with 8 percent still undecided.

The survey was conducted for Reuters and Boston television station WHDH by Zogby International.

The most startling feature of the poll was the way McCain pulled away from Bush in the final day of campaigning. In weekend polling, he had led Bush by 5 percentage points. He doubled that in the last 24 hours.

"By all appearances, McCain is picking up strongly among independent voters and new voters and momentum is on his side," said pollster John Zogby.

Both Bradley and McCain badly need to win Tuesday's primary, the earliest in the nation, to have any chance of catching established front-runners down the road.

Gore and Bush retain superior national organizations and lead national polls by wide margins.

In past campaigns, voter opinion has shifted decisively in the final weekend before the New Hampshire primary, and that appeared to have happened again.

"New Hampshire Democrats are a feisty bunch and undecided voters could tighten this race a little. However, Gore has clearly solidified among core Democratic voters," Zogby said.

Two other polls showed similar trends. A CNN/Gallup poll showed Gore leading Bradley 51-45 percent and McCain ahead of Bush, 42-32 percent. A Quinnipiac College poll had Gore over Bradley, 53-36 percent and McCain ahead of Bush 39-29 percent.