As construction workers milled at the site of a new state Senate office building by the Capitol, GOP candidate for governor Jeff Johnson held a press conference off to the side to renew his frequent criticism of the project.

Johnson and three other Republicans are in the final sprint toward Tuesday's primary election, where the party will pick its opponent for DFL Gov. Mark Dayton. Around the same time Johnson criticized the office building as wasteful and tried to link it to Dayton, he drew a rebuke over taxes from GOP opponent Kurt Zellers.

"Jeff Johnson is carrying the same tired ideas that Mark Dayton tried to force on Minnesotans just last year," read a press release from Zellers, the former House speaker. It's a reference to a May 2013 interview in MinnPost where Johnson expressed support for lowering the overall sales tax rate but shrinking the number of products and services exempt from it. That's similar to a tax reform proposal from Dayton in early 2013 that he later abandoned.

Johnson cited his strong rating from the Minnesota Taxpayers League and his record on the Hennepin County Board as evidence for his opposition to tax increases. He said he would seek to cut taxes as governor, and would veto any tax increase from the Legislature.

"Kurt's probably recognized that he's a ways behind and needs to go on the attack," said Johnson, whose endorsement from the state GOP has contributed to a view among many Republicans that he has a slight edge heading toward Tuesday's vote. The other two contenders are Scott Honour, a businessman and political newcomer, and Marty Seifert, the former House minority leader.

Johnson said he preferred to focus his criticism on Dayton, not fellow Republicans. It was Johnson's second press conference at the site of the new Capitol office building in less than six weeks. He called the project, being built with $77 million in taxpayer funds, "symbolic of Dayton's priorities."

The Minnesota DFL noted that several prominent Republican lawmakers, Sen. Dave Senjem and Rep. Matt Dean, were involved in the official process around moving the project forward, and voted in favor of hiring an architect and construction company.

Dean, in response to the DFL criticism, said while he did serve on the appointed panel that signed off on hiring an architect and contractor, that he has repeatedly stated his larger opposition to proceeding with the building . He said he didn't feel the state should specifically penalize architects or contractors for a project that had already been approved.

Johnson said if he were to become governor, he would seek to cancel construction if it's not too far along. If the state has already invested tens of millions, he said, he would try to re-purpose the building for some other state use besides the Senate.

The Honour campaign also took its turn criticizing the office building. The campaign released a video of his running mate, state Sen. Karin Housley, holding up a series of signs mocking the project.