TRENTON - Republicans railed yesterday against Gov. Corzine's proposal to earmark millions of dollars for open-space preservation only if lawmakers allow him to lease state assets, calling the plan "an attempt to blackmail the Legislature."

Corzine opposes issuing bonds to renew funding for the Garden State Preservation Trust, as has been done in the past with voter approval. He said he preferred to fund open-space acquisitions and historic preservation with proceeds from leasing toll roads, the lottery, or other state assets.

"Gov. Corzine knows of the strong support for Green Acres funding, and this is nothing less than an attempt to blackmail the Legislature to support his risky asset-monetization scheme," Assembly Republican Leader Alex DeCroce of Morris County said.

Sen. Nicholas Asselta (R., Cape May) called the Democratic administration's plan "irresponsible," and accused the governor of "holding open-space and farmland preservation hostage" to the scheme.

The popular open-space and historic preservation program has preserved nearly 300,000 acres since 1999, but is nearly out of money for conservation.

Environmentalists have been scrambling to meet a June deadline to get a question on the fall ballot asking voters to infuse the fund with $175 million a year for 30 years from the state sales tax.

The Corzine administration wants that legislation quashed, saying it would increase the state debt.

"The governor is committed to this program," Corzine spokesman Brendan Gilfillan said, "but he believes we have to find a funding source that is recurring. Ideally, that would result from asset monetization."

A coalition of 90 environmental, historic and community groups has been working to get the trust reauthorized through the sale of bonds. In a statement yesterday, the Keep It Green Campaign said it was concerned that vital lands would be lost to development while politicians argued the merits of leasing the New Jersey Turnpike or other assets.

Corzine put $25 million into the proposed fiscal 2008 budget to keep the fund going until a permanent solution could be found.

The bill that would put the funding question to voters cleared an Assembly committee Monday, but must clear the Appropriations Committee before it can be posted for a full Assembly vote. The Senate has yet to take up the measure.