SAN FRANCISCO, Calif. (KCBS)  -- After weeks of back room negotiations, Mayor Gavin Newsom has now signed on to a plan to force most San Francisco businesses to pay for health coverage for their workers.

As late as last Thursday, Mayor Newsom said he opposed the health coverage legislation by Supervisor Tom Ammiano.

Now Newsom confirms that with some changes worked out, he's ready to jump on board.

"Because it's changed," he told KCBS Reporter Barbara Taylor about the reason for the shift. "The mandate's changed dramatically. We worked through the night last night.

There had been two universal health care plans in the hopper: one from the Mayor, and one from Ammiano. The two were merged into one last week.

Newsom had proposed a low cost health access plan; Ammiano was pushing all along to have businesses pay to insure their workers.

"A lot of amendments have been made that make this work from my perspective," Newsom said. "We've had to adjust and amend and consider and reconsider. We've got triggers, we've got a phase-in; that's very significant."

The biggest change is that employers would not have to pay for health coverage if the worker is already covered as someone's dependant.

Still, Nathan Naman of the Committee on Jobs emerged from the latest hearing saying the legislation still isn't prepared for passage.

"The thing that struck me is Supervisor [Chris] Daly saying that it's reasonable in exchange for six hundred job losses to move forward with this," he told KCBS's Taylor. "It is not ready for prime time; this needs a lot more work."

Even though businesses say that they will be forced to fire workers to pay the tab, labor is thrilled with this agreement, and a vote is expected at the full Board of Supervisors meeting next week.

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