Time is running out to get an open space referendum on the November ballot in New Jersey.

A proposed constitutional amendment would dedicate up to $200 million of state tax revenue to preserve open space, farms and historic sites for each of the next 30 years.

The Legislature needs to approve the measure by a two-thirds vote within the next week and a half so it can appear on the ballot for voters to decide.

It's not clear if that will happen, according to Senate Environment Committee chairman Bob Smith.

"People are on vacation and that makes it difficult, but that being said we're going to try out best to get the appropriate number of people to the session and get the appropriate vote," said Smith, D-Bergen.

The chairman of the New Jersey Keep It Green Coalition said approval of the proposed constitutional amendment is a matter of urgency.

"There are so many important projects that are essential to quality of life and protecting natural and historic resources around the state that hang in the balance, and if they fail to act we're essentially going to see decades of very successful bipartisan preservation efforts come to an end," said Tom Gilbert.

Assemblyman John McKeon, D-Essex, questions whether there would be enough support from Republican lawmakers to pass the measure.

All the money from previous bond acts has been allocated, and supporters say a long-term funding source is needed to continue preservation efforts.