Topeka ? Legislative negotiators agreed Thursday that a proposed amendment to the Kansas Constitution banning gay marriage also should prohibit civil unions and the extension of other legal benefits to same-sex couples.

The language is similar to a proposed amendment adopted in March by the House. The Senate last month rejected a narrower version that only addressed gay marriage.

Two-thirds of both chambers must approve the same language for the proposed amendment to the Kansas Constitution to be placed before voters in November.

Negotiators were also drafting an explanation of their proposal for voters, to appear on the ballot with the proposition. They planned to meet again Friday.

Senate negotiators said they do not know whether the compromise language would win approval in their chamber, which would consider the measure first. House adoption is considered likely.

But Senate President Dave Kerr, R-Hutchinson, said after negotiators met Thursday: “I think that it has a good chance.”

The House negotiators’ position is consistent with the proposal their chamber adopted in early March, addressing gay marriage, civil unions and the granting of benefits to unmarried couples.

But in late March, senators rewrote the proposal so that it contained only a ban on gay marriage, without any mention of civil unions or benefits associated with marriage. It was ultimately rejected when some supports of a ban on gay marriage said it was too weak.

Supporters of the House proposal, including some clergy, had been hoping public pressure would persuade the Senate to adopt the House language.

The Rev. Joe Wright, senior pastor of Wichita’s Central Christian Church, said banning gay marriage in name only isn’t enough. Kansans, he said, do not want to see marriage-like institutions, such as civil unions, created for gay couples.

“We’re concerned not only with protecting the name of marriage but the institution of marriage,” said Wright, who attended the negotiators’ meeting.

Meanwhile, the simple ban on gay marriage is unacceptable to supporters of gay and lesbian rights.

“We’re opposed to any language that is discriminatory being put in the constitution and on the public ballot,” said Tiffany Muller, chairwoman of Topeka’s Equal Justice Coalition. “Trying to preclude any future granting of any rights or equality is reprehensible.”

Gov. Kathleen Sebelius — who has no say in whether a constitutional amendment goes on the ballot — continued to question the need for the proposal.

“What’s the rush?” Sebelius said during a brief news conference Wednesday. “I believed and continue to believe we do not need to amend the constitution.”

Kansas already has a statute that says the state only recognizes marriage between one man and one woman.

Massachusetts had no such law on its books last year when its highest court declared it unconstitutional in that state to prohibit gay marriage. But backers of the proposed Kansas measure say enshrining the state’s policy in the Kansas Constitution would prevent a court here from striking down the statute and lend support to long-cherished values and families.

Some critics say the proposal would write discrimination into the state constitution. Others, including some senators, have said going beyond a simple ban on gay marriage invites a legal challenge in federal court.