The Minnesota Supreme Court on Thursday cleared the way for a controversial taxpayer-funded office building for state senators with a roadblock to a lawsuit that sought to challenge the project.

The building has become a lightning rod at the Capitol this year, with Republicans vowing to make it a core election issue as a symbol of what they consider DFL excess. DFLers have said the project is needed to handle the overflow during the Capitol’s long-range restoration and what will be a permanently smaller space there for legislators.

The state’s high court ruled that former Republican Rep. Jim Knoblach would have to post an $11 million surety bond if he wanted his challenge to the project to continue. He said he can’t afford to post a bond of that size.

“Requiring a member of the public to come up with $11 million in a case like this is a chilling precedent to a citizen raising a constitutional challenge,” he said.

State lawyers had argued that Knoblach should be required to post the bond in the event that his suit forced delays and cost overruns on the project. The Minnesota Court of Appeals ordered him to do so. The Supreme Court on Thursday refused to overturn the order in a brief ruling signed by Chief Justice Lorie Gildea.

Knoblach’s suit rested on a technical argument, that legislators violated the state Constitution by including most of the project’s funds in a tax bill, not a construction bill. But Gildea wrote that “the merits of the constitutional challenge raised in this litigation are not before the court.” The appellate court ruling being considered by the Supreme Court dealt strictly with whether a surety bond should be posted. The rejection by the high court left Knoblach with no path forward on his underlying suit.

The $90 million building, of which $77 million will come from taxpayers, is planned for a site across University Avenue on the north side of the Capitol in downtown St. Paul. The remaining $13 million is projected to come from parking fees. Upon completion, the building will provide permanent office space for all 67 state senators, not limited by party. State officials want it built quickly, so that it can house legislators when they’re displaced from their Capitol offices by the ongoing large-scale renovation.

The state Department of Administration had hoped to break ground July 1. Agency spokesman Curt Yoakum said Thursday that date is no longer in reach but said construction would begin as soon as possible. Completion could take up to 17 months.

Republican legislators have blasted Gov. Mark Dayton and House and Senate DFL majorities for signing off on the project, which its critics call wasteful and unnecessary. GOP leaders have said they will try to make it an election issue for DFL House members who are up for re-election in November, as Republicans try to regain a majority in that chamber.

But the project’s defenders, chief among them DFL Senate Majority Leader Tom Bakk of Cook, have argued that the Senate needs new permanent space because the House and governor’s office will be getting more space in the renovated Capitol.

Knoblach, a small-business owner, represented St. Cloud in the House from 1995 to 2006. He is seeking a comeback by mounting a challenge to DFL Rep. Zachary Dorholt.