City Council moved Thursday to approve a new contract for Philadelphia's largest municipal union, which would require those workers to contribute more to their pensions.

Council members, however, were not yet ready to make the same demand of themselves.

The legislation was introduced only after it was stripped of a proposal that about 5,000 other city employees - including elected officials - also pay the higher pension costs.

Council President Darrell L. Clarke acknowledged the legislation had been watered down from what the Kenney administration had proposed. He insisted that Council members were not trying to dodge paying more toward their pensions.

"We are working with the pension representatives and the administration on crafting legislation that will reflect changes in exempt and elected officials," Clarke said, naming the groups that would have been affected under the original legislation.

The city's pension system is dangerously underfunded, having enough on hand to cover only 45 percent of its $10.6 billion obligation.

In July, AFSCME District Council 33 agreed to have its 9,000 members pay more into the fund by implementing a tiered system under which employees' contributions increase as their salary does. New members will be put in a "stacked hybrid" pension fund, which combines a traditional pension plan and a 401(k).

City officials have said they will seek similar terms with the other unions. Kenney's spokeswoman, Lauren Hitt, said it was only fair for other city employees to also make the concession.

"If we're going to ask for sanitation workers to make these sacrifices, then it's appropriate we share in that burden," she said.

Though the new contract for D.C. 33 offers employees raises, that benefit was not extended to the other employees included in the proposal from the administration.

Councilman Curtis Jones Jr. said his colleagues were not keen on a change that would effectively amount to a pay cut, but said that was not the primary concern. Instead, he said, he worried the change would unfairly pressure other unions to also accept the terms. "It was the signal it sends to our labor partners: Do this or else," he said. "So we need to be clear: Is that the signal we want to send?"

Other Council members said they only learned of the proposal Wednesday afternoon and needed more time to review it.

"I think in general the response was positive," said Councilman Allan Domb, a real estate mogul who gives his Council salary to charity and has been focused on pension reform. "I just think they wanted some time to digest all of it."

Clarke noted Council members have seen their pension costs increase in recent years. He said legislation addressing elected officials and exempt employees could be introduced as soon as next week.

Any changes for elected officials would not go into effect until after the next election. Asked if the changes would mirror the concessions in the D.C. 33 contract, Clarke said he did not know. But he suggested the concessions could be greater, saying he is not sure if other proposals to date "are enough."

After this story first appeared on philly.com, Clarke's spokeswoman, Jane Roh, sent an email, raising a new concern. She said a change that would amount to a pay cut for thousands of city employees "should not be legislated with only a day's notice and no discussion with those affected."

tnadolny@phillynews.com215-854-2730@TriciaNadolny