An amendment to Bill 35, the Municipal Conflict of Interest and Campaign Financing Act, was tabled Thursday by Ste. Rose Progressive Conservative MLA Stu Briese.
The Tories say changing the rules three-quarters of the way through a term is not what any of the sitting councillors signed up for.
Briese said if the bill is passed this session, but doesn't go into effect until after the 2010 election, each candidate can make a personal decision about disclosing information about assets and conflicts of interest.
Mayor Sam Katz has already called the bill a "slap in the face to city council" because Winnipeg had earlier rejected a proposed ban on union and corporate donations.
Katz said new rules imposed by the bill could increase the power of incumbency and inject party politics into a nominally non-partisan city council.
Briese's amendment also acknowledges concerns raised by the Association of Manitoba Municipalities.
"We understand the assumption that by entering public office your life becomes more public," AMM President Doug Dobrowolski told the Standing Committee on Legislative Affairs Sept. 28. "However, there was never a commitment to have your financial disclosure information available to anyone to review at any time. It is unjust to change the rules on this important issue in the middle of a mandate."