Deep skepticism among some City Council members about the Kenney administration's promises to meet diversity goals on Rebuild construction sites was on full and fiery display Wednesday.

At a hearing on Rebuild, the administration's $500 million plan to renovate parks, recreation centers and libraries, Council members picked apart the administration's agreement with the building trades. Members said it wouldn't open doors to union membership for those long denied access.

"There's nothing of, 'We're committed to taking 80 percent of the people that go through the program and make them union, no matter what,'" Councilwoman Maria Quinoñes Sánchez said of a pre-apprenticeship program being developed by the Philadelphia Building and Construction Trades Council. "It doesn't have numbers. It has aspirational goals."

At the end of the nearly five-hour hearing, Council did not approve the Rebuild plans, saying it would reconvene and potentially vote on Monday, and signaling continued negotiations between the body and administration in the days ahead. Council also, about 7 p.m., approved a long list of amendments to the legislation, including some that would give individual Council members dramatically more control over the project.

Lauren Hitt, Mayor Kenney's spokeswoman, declined to comment on the specific content of those amendments.

"This isn't the final version," Hitt said. "We still expect to see some change. And we haven't really had a chance to digest it yet, so we can't comment in great detail."

Rebuild, which is to be paid for with revenue from the city's sweetened beverage tax, is expected to involve renovations at 150 to 200 individual sites over more than five years. Officials see it as a vehicle for social and economic change through jobs created as facilities are improved or rebuilt, and through the creation of community centers that deliver essential services and strengthen neighborhoods.

The administration has also pitched the project as a means for creating more diversity on worksites, saying that if methods used here are successful, they can be replicated and begin to address the longstanding lack of diversity in the city's building trades.

Some Council members on Wednesday said those methods lack the teeth to be effective and to reach diversity goals.

In response, the administration, raised the bar, saying it has increased the minority participation goal for the project from 40 percent to 45 percent to align with the city's most recent diversity study. And it committed to hitting that target in Rebuild's first year, something officials previously said would not come until much later.

"We've been working on it," Rebuild executive director Nicole Westerman said. "We've been talking. We've been figuring things out. We think we can do it."

Councilwoman Cindy Bass was unconvinced.

"If we're not ready, then we need to shelve Rebuild until we are ready," Bass said.

"We are ready, councilwoman," Westerman replied.

"OK, we'll see. We'll see," Bass said. "We hope so. Because we want it to be right."

Workforce diversity is just one of several unsettled issues.

Over the last several months, Council members and the administration have clashed repeatedly over the project's funding structure. Under the administration's plans, the city would have nonprofit partners, known as project users, temporarily lease the sites and act as project managers for the work.

Council President Darrell L. Clarke has called the arrangement a path to privatization, something Kenney's team denies. Among the amendments passed Wednesday is one that would allow the Council member representing the area where the project is located to chose "an alternative project delivery method," putting a core decision currently in the administration's hands in Council's.

Council members sought to pick up ground in other areas, with the issue of site selection growing particularly thorny.

Administration officials have pledged to work with Council members to select which sites will be renovated and when. Bass wanted to know what would happen in the case of a disagreement, then dug in when administration officials repeated their plans to negotiate in good faith. "That's not an answer," Bass said.

Brian Abernathy, the city's first deputy managing director, said the administration had recently agreed to let Council approve a site list annually. If a Council member disagrees with plans for an individual site, he said, he or she can vote against the list.

"It would be so much simpler if the administration would say the district Council person will have the final say," Bass said. "Because that's what you're saying in a roundabout sort of way. … Let's just keep it real with each other."

"I am," Abernathy said back. "And I believe the administration has moved significantly on this issue. We're looking forward to Council being our partners, but I don't believe the administration is willing to move any further at this point."