Voters in the key swing states of Colorado, Iowa and Virginia support marriage equality, a poll has found.

The Quinnipiac University Poll conducted telephone surveys with roughly 1,200 voters in each state from July 9-20.

“Voters in Colorado, Iowa and Virginia who side with the Catholic Church on the environment would seem to part ways on the issue of same-sex marriage,” said Peter A. Brown, assistant director of the Quinnipiac University Poll.

“Businesses can not refuse service to gays, voters say. But they are split on whether a business owned by a person who views same-sex weddings as sacrilegious should be forced to serve homosexuals,” he added.

Support was strongest in Colorado, where 59 percent back such unions, followed by Iowa (51%) and Virginia (49%)

By a wider 61-34 percent, voters in Colorado oppose a constitutional amendment allowing states to decide the issue. Opposition in Iowa and Virginia was nearly identical at 55-40 percent.

Majorities in Colorado (60%), Iowa (58%) and Virginia (61%) say businesses should not be allowed to refuse service to people based on sexual orientation. Voters, however, are split on whether a business owner who cites religious beliefs should be allowed to deny service to gay men and lesbians. In Colorado, 48 percent say the owner should not be allowed to deny service, while 45 percent disagree. Iowa voters are split 46-46 percent. Forty-seven percent in Virginia say the owner should be allowed to deny service, while 45 percent disagree.