A bill recognizing same-sex civil unions passed in the Connecticut House of Representatives on Wednesday, but not without the addition of an amendment defining marriage as an act between a man and a woman.

The House voted 85-63 in favor of the bill, moving Connecticut one step closer towards becoming only the second state to establish civil unions and the first to do it as a result of legislation rather than court order. But the House dealt a blow to advocates of same-sex marriage by attaching the controversial amendment. The state Senate, which overwhelmingly passed the original legislation last week, will now have to reevaluate the bill.

Gov. Jodi Rell, a Republican who has announced her support for civil union legislation but has also expressed opposition to same-sex marriage, released a statement declaring her willingness to sign the modified bill into law should it reach her desk.

“The bill that emerged from the House tonight is stronger and clearer than the legislation passed by the Senate last week,” Rell said in her statement. “It is now up to the Senate to act. If they pass the bill in accordance with the House, I will sign it.”

State Rep. Mike Lawlor, a Democrat and the bill’s sponsor in the House, expressed his satisfaction with the House’s decision and said that he hoped Wednesday’s vote would pave the path towards legalizing same-sex marriage in Connecticut.

“I think it was a very bipartisan vote,” Lawlor said. “I think this shows that it’s not just activist judges. It’s the will of the people taking place … My sense is in a few years, public opinion will shift in support of same-sex marriage as well.”

Proponents of the civil union bill downplayed the significance of the marriage amendment, which largely restates definitions of marriage already in the lawbooks.

State Rep. Patricia Dillon, a Democrat from New Haven, called the civil unions bill “legislation at its best” and praised the hard work and thoughtful process leading to the bill’s passage. She said the amendment would delay proceedings but probably would not cause the Senate to in any way retract its support of the bill.

“The amendment doesn’t do harm to the core of the bill,” Dillon said. “It is not the same as some of the old [Defense of Marriage Acts]. The civil union has the same benefits of marriage, and marriage is defined the same as it is elsewhere.”

Hundreds of civil union opponents rallied on the steps to the capitol in Hartford throughout the day, the Associated Press reported. The opponents vowed that their fight would continue and hoped the Senate would reverse its ruling from last week.

Republican state Rep. Al Adinolfi, an opponent of civil unions, said he was disappointed by the outcome but that’s the vote had been a lot closer than he anticipated.

“The bill destroys the age-old definition of marriage,” Adinolfi said. “I would love to see the Senate revisit this. It’s a possibility because there are a lot of constituents who will try to get in touch with their senator, and that may lead to some switches.”

Adinolfi said he regarded the marriage amendment as no more than a minor victory, reaffirming already accepted definitions of marriage.

Legislators said they expected that the Senate would return to the bill as early as next week, allowing for the possibility that civil unions could become Connecticut law within the next few months.