AUGUSTA, Maine (AP) – Supporters of Maine’s same-sex marriage law continued Friday to collect far more campaign contributions than their opponents in a referendum that’s being watched nationally.

NO on 1/Protect Maine Equality said in its campaign finance report to the state that it has raised $4 million in its campaign to keep Maine’s same-sex marriage law on the books. That compares to the $2.5 million raised by Stand for Marriage Maine, which forced the people’s veto vote through a petition drive.

Despite the fundraising advantage, NO on 1 was taking nothing for granted, said campaign manager Jesse Connolly.

“We know this is going to be a razor-thin election,” Connolly said.

NO on 1’s report to the Commission on Governmental Ethics and Election Practices showed multiple pages of donations in the $50-$1,000 range, with exceptions from some individuals, including Donald Sussman of Portland at $300,000.

On the other side, the National Organization for Marriage was by far the biggest contributor to Stand for Marriage Maine’s political action committee, with $1.1 million during the latest reporting period. The Roman Catholic Diocese of Portland gave another $152,600.

Throughout the campaign, the Princeton, N.J.-based NOM has donated a total of $1.5 million while the diocese has kicked in $550,000, which includes money from out-of-state dioceses and individual donors.

Stand for Marriage Maine remained at a financial disadvantage to their opponents, but that was no cause for alarm, spokesman Scott Fish said.

“Our hope is that this ... will close the gap. We are working hard to get our message out,” said Fish, adding that an intense fundraising push will continue in the days ahead.

George Smith, a State House lobbyist and commentator who has not taken sides on the issue, said a funding advantage like NO on 1’s “almost always guarantees a win.”

But Smith said a problem the repeal opponents still face is that the ballot, which includes two anti-tax questions and one to repeal a state school consolidation law, “is loaded with great issues for conservatives.” Smith believes turnout will be a key element in the off-year vote.

Political action committees were required to file their final campaign contribution reports with the campaign before the end of the day Friday.

Earlier reports showed NO on 1 had raised $2.7 million, compared to $1.1 million for Stand for marriage Maine.

With its Nov. 3 referendum, Maine is seen as a testing ground for gay-marriage laws around the country. Six states recognize gay marriage either by legislative action or court order, while 30 states have constitutionally banned it.