JEFFERSON CITY — A bill that one lawmaker said would mean "the most radical undermining of open records and transparency law in state history" passed the Missouri House on Thursday.

But the bill's sponsor said he'll work to tamp down the most contested part of the bill, which also imposes campaign contribution caps on local candidates and applies other ethics restrictions to local officeholders.

At issue is an amendment adopted on the House floor Monday that would keep records from being public if they are "received or prepared by or on behalf of a member of a public governmental body" and consist of "advice, opinions and recommendations in connection with the deliberative decision-making process of said body."

Backers have said the intent is to shield correspondence between constituents and lawmakers, which recently became subject to the state's Sunshine Law following voter approval of a constitutional amendment in November.

But Rep. Jon Carpenter said the bill passed by the House would allow almost all government records to be closed.

"Almost unquestionably if this bill passes, it's going to be the most radical undermining of open records and transparency law in state history," the Kansas City Democrat said Thursday on the House floor.

Republican bill sponsor Rep. Shamed Dogan, of the St. Louis suburb of Ballwin, told concerned colleagues on the House floor Thursday that he'll work to tone down the contested language as the measure makes its way through the state Senate.

The Senate appears likely to change the bill. Republican Senate Majority Leader Caleb Rowden said passing legislation "is a multistep process for a reason."

"We're going to do our very best to make sure that the things that we feel are necessary for the privacy of our constituents and that sort of interaction is covered, without maybe making it too broad and really probably undoing or upending what the voters told us last November," Rowden said.

The underlying bill would impose a $2,000 cap on campaign donations per local candidate each election. It would also extend other ethics policies that lawmakers and statewide officials now face to local officials, including a $5-a-day lobbyist gift limit and a two-year ban on lobbying after leaving office.