Miami commissioners on Thursday put off Mayor Manny Diaz' star-crossed proposal for remaking environmentally scarred Virginia Key after a stream of activists complained the plan doesn't do enough to safeguard and showcase the island's natural treasures.

The deferral of the Virginia Key plan until May means the term-limited Diaz, who has been pushing to win approval of several key goals less than a month before leaving office, won't be at City Hall to see the completion of one of the cornerstones of his administration.

But the commission, by a 4-0 vote, did approve Diaz's ambitious blueprint for more than 200 new miles of bicycle lanes and routes throughout the city, as well as a package of ``green'' measures that include requirements for heat-dispersing roofs for new commercial and residential projects. Commissioner Angel Gonzalez was absent.

In deferring the Virginia Key proposal, the commission made plain its goal is to give city planners time to incorporate ideas from environmentalists, parks activists and others who have been working on alternative ideas for the barrier island's restoration.

Still, Diaz said he was pleased the initiative has come this far. ``We're talking about it. You've got to move it forward,'' he said.

Critics of the plan, which has been significantly pared back from an earlier version, contend it still contains too much concrete and asphalt and not enough on the ecological end of the scale.

``What's the rush at this point? Take the time to do it right,'' Urban Environment League vice president Greg Bush urged commissioners, calling the plan ``close but still inadequate.''

The commission did, however, endorse a proposal by Commissioner Marc Sarnoff, whose district includes the publicly owned Key, to immediately start work on two pieces of the plan: a mountain bike course on the island's north point and an evaluation and cleanup of a toxic old dump, which is now capped, at its center.

Cycling groups have offered to build and maintain the course at no cost to the city. Miami-Dade County, meanwhile, has set aside $45 million for the landfill, where the Virginia Key plan contemplates construction of athletic fields.

City Manager Pete Hernandez said Miami is soliciting proposals for evaluation of the illegal former dump, which shares the 1,000-acre island with nature preserves, a sewage treatment station, restored beaches and the historic Miami Marine Stadium.

The Key master plan covers some 250 of those acres, focusing on the Marine Stadium area. It includes two publicly owned marinas and a rowing center as well as the landfill .

The fate of the historically designated stadium has been another sticking point. An earlier proposal would have done away with it, and a later version also called for an extensive athletic complex, including an array of parking garages atop the landfill, as well as a commercial ``village'' on the stadium parking lot.

Those were markedly scaled back after two city boards unanimously turned down the plan. But activists continued to question how appropriate surviving elements were for the ecologically sensitive island.

Activist Nina West called the latest proposal a ``hodge-podge'' of disconnected ideas. ``We could have a jewel here,'' she said.

In contrast, Diaz's bike plan encountered no objections.

The blueprint is designed for gradual implementation over 20 years, as roads are resurfaced, and the needed work -- mainly striping and signage -- is relatively inexpensive. The aim is to have an interconnected network of designated routes for commuting and recreational cyclists covering much of the city.

The plan also identified nearly 1,000 public locations across Miami for bike racks and sheltered bike parking.

The commission also approved a new requirement for commercial and residential projects requiring inclusion of bicycle parking.

Staff writer Charles Rabin contributed to this story.