TOPEKA, Kan. — Top Republicans barely overcame bipartisan skepticism Thursday to push an education funding plan through the Kansas Senate, though even its top GOP leader had doubts that the measure would satisfy a court mandate to increase spending on public schools.

The vote was 21-18 on a bill that would phase in a $274 million increase in school funding over five years. Republican supporters said it was a good-faith effort to address the issues raised in a Kansas Supreme Court ruling last fall while not creating budget problems that would force lawmakers to increase taxes within two years.

The Supreme Court ruled in October that the state's current aid to its 286 local school districts of more than $4 billion a year is not sufficient for legislators to fulfill their duty under the Kansas Constitution to finance a suitable education for every child. Asked later whether the bill would satisfy the high court, Senate President Susan Wagle said she wasn't sure.

"I'm not sure anything satisfies the Supreme Court," the conservative Wichita Republican told reporters.

In the 40-member Senate, the bill split the 30 Republicans. Some of Wagle's fellow conservatives believe the court is improperly encroaching on the Legislature's power to determine how state funds are spent. They argued that the bill would spend too much money, even though a rival House plan would boost spending almost twice as much.

The nine Democrats and one independent member voted against the bill, joining with some GOP moderates who didn't think it provided enough money.

"This bill doesn't get us where we need to be," said Senate Minority Leader Anthony Hensley, a Topeka Democrat. "This bill is woefully inadequate in terms of the funding it's providing."

Wagle had private meetings with Republicans to push them to vote yes. Senate GOP leaders also tried to sell fellow Republicans on voting for the bill to keep lawmakers moving toward meeting the court's mandate. The justices gave the attorney general until April 30 to report on how legislators fixed the problems the court identified.

"We're going to haggle over the dollars," Senate Education Committee Chairwoman Molly Baumgardner, a conservative Louisburg Republican, told fellow GOP senators during a caucus.

The House plan would phase in a roughly $520 million increase in education funding over five years, and Republican Gov. Jeff Colyer publicly endorsed it Wednesday. The final version of a plan will be drafted by negotiators for the two chambers.

Colyer has called on the Republican-controlled Legislature to pass a bill before taking an annual 2½-week spring break that is scheduled to start Saturday. Lawmakers return from that break April 26 — only four days before the court's deadline.

Supporters of the House plan contend the state can cover the additional spending with the annual growth in the state's tax collections, which have been stronger than expected for 10 consecutive months.

But, armed with five-year projections from legislative researchers, top Republican senators argued that supporters of the House plan are being far too optimistic. Senate GOP leaders said passing the House plan would force the state to increase taxes — possibly next year — even though Colyer has said lawmakers should avoid a tax hike and most lawmakers want to avoid one.

The Supreme Court did not set a specific spending target in its October ruling but hinted that it could be $650 million more a year. The four school districts that sued the state in 2010 argue that the figure is even higher.

But some Republicans supporting the Senate plan predicted that the Supreme Court would accept it because of how it targets its new funding for specific programs to help ensure that young children don't fall behind in school early. Others said the new money also builds on past increases.

"It's more than enough," said Sen. Ty Masterson, a conservative Andover Republican.