Mayor Bloomberg’s plans to put $14 million into the redesign of Union Square Park put him in a rare face-to-face confrontation protesters yesterday and could put him at odds with voters in the neighborhood as he prepares for re-election next year.

Amid chants of “Parks are for kids, not for restaurants,” Mr. Bloomberg unveiled a proposal to reconstruct Union Square Park.

In addition to installation of a year-round restaurant, the plan calls for the unification and expansion of two existing playgrounds in the park, and the creation of a paved plaza for the square’s popular Greenmarket.

Construction will begin this time next year and the farmers’ market, the mayor said, will stay open during the entire renovation.

The city has kicked in $8 million for overhaul and an additional $6 million in private funds has been raised, including a donation of $5 million from an unnamed private citizen, to make up the balance.

“With the help of the Union Square Partnership over the last 20 years, the park and neighborhood have been transformed from an area once synonymous with blight and inaccessibility to a hub of restaurants, commercial, academic, and residential life,” Mr. Bloomberg told reporters at Union Square.

Now a public/private partnership will take it the rest of the way, he said.

The mayor said the $14 million plan was put together after taking into account community concerns about paving, insulation of the north end of the square from traffic, and the need to create a corridor around the square from Broadway.

Even so, nearly a dozen protesters wielding “for sale” signs and passing out flyers made clear they didn’t like the mayor’s proposal.

They want the playground to be expanded into a larger area than the plan the mayor has endorsed. They want access for physically challenged children, and they don’t want a restaurant to take up space that could otherwise be used for more playground equipment.

As Mr. Bloomberg walked back to his motorcade, the protesters resumed their chant against a private restaurant in the park.

The mayor gave them a shrug and said, “How do you expect us to pay for parks?”

His chief spokesman, Ed Skyler, said a restaurant had been in the park for the past five years so the mayor wasn’t taking any space from the playground.