Four former New Jersey governors have urged the state Pinelands Commission to reject a proposed gas pipeline through protected forest, saying approval would "compromise the integrity" of the Pinelands' long-standing management plan.

Deviating from the management plan would also "encourage future development" in protected areas, former governors Brendan T. Byrne, Thomas H. Kean, Christine Todd Whitman, and James J. Florio wrote in a letter released Wednesday.

"We understand the reasons that are presented, often compellingly, to waive environmental protections in what may seem at the time to be unique or extraordinary cases," they told the 15-member commission.

But by adhering strictly to the Pinelands development plan, in place since 1981, "utility companies, developers and others in government and industry [will] form their own long-range plans to comply with the long-range vision."

South Jersey Gas is seeking a variance from the commission that would allow it to lay a 24-inch natural gas pipeline through 10 miles of protected forest where new utility lines are barred unless they primarily serve local residents.

Commission staff have determined that the line does not meet the local-service standard, but say four alternative routes would traverse wetlands or require extensive drilling under Great Egg Harbor River, and likely be more problematic.

The commission is scheduled to vote Jan. 10 on whether to issue a variance, known as an intergovernmental memorandum of agreement. The state Board of Public Utilities is petitioning for the variance on behalf of South Jersey Gas.

While the pipeline has the support of Gov. Christie, the outcome of the vote seems uncertain.

On Dec. 6 the state attorney general's office ordered commissioner Edward Lloyd to recuse himself from deliberating or voting on the pipeline project, alleging that he had a conflict of interest.

Lloyd, who two days earlier had sharply criticized the process by which the line was being reviewed, has said he has no conflict of interest.

Opponents of the line, including the Sierra Club and the Pinelands Preservation Alliance, allege that Lloyd, an environmental law professor, was removed because his opposition could have derailed the project.

As proposed, the line would run nearly 22 miles from Maurice Township in Cumberland County to a proposed gas-powered electrical power plant in Upper Township, Cape May County.

The plant would replace a coal-fired electric generation plant operated by the BL England Corp., which has for decades violated state air pollution regulations. The state Department of Environmental Protection has endorsed the pipeline on those grounds.

The governors' letter, dated Dec. 12, was submitted to the commission as part of its public hearing record. It was released Thursday by a consortium of environmental organizations opposing the project.

In their letter, the four describe the 1.1 million acre Pinelands, which span parts of seven counties, as "one of New Jersey's most precious resources."

They also call the management plan - which subdivides the vast tract into commercial, residential, agricultural, and forest areas and identifies their permitted uses - as "the nation's most successful program to save vulnerable natural resources" in a highly urbanized state.