TRENTON A multistate agency that has spent years developing regulations for natural gas drilling in the Delaware River watershed abruptly canceled a key vote scheduled for Monday after two members announced their opposition. The Delaware River Basin Commission said Friday it was postponing a vote on hydraulic fracturing, or fracking, to give the agency's five commissioners more time to review the draft regulations. Pennsylvania Gov. Tom Corbett said the commissioners failed to agree. The DRBC said no new date had been set. "Pennsylvania is ready to move forward now," Corbett said in a statement released Friday. "We have demonstrated a willingness to compromise and to address issues brought forth by other members of the commission. We have worked with our commission partners in good faith, and it is disappointing to not have these efforts reciprocated." But New York's Attorney General, Eric Schneiderman, said an environmental risk-assessment is needed to win public confidence and ensure that the commission's actions are based on science. "This delay further demonstrates that the proposed regulations for fracking in the Delaware River Basin are not ready to see the light of day," Schneiderman said in a statement Friday. "Without a full, fair and open review of the potential risks of fracking in the basin, the public will continue to question the federal government's ability to protect public health and environment." The federal Environmental Protection Agency is studying the effects of fracking, with a draft report due next year. The postponement of a vote came hours after Delaware Gov. Jack Markell told fellow commissioners he would not support the regulations because of concerns over drinking water protections. Earlier, New York announced it would vote no. New Jersey and Pennsylvania had not announced how they would vote, but it was believed both would vote yes. With two Democrats prepared to reject the rules and two Republicans signaling their support, passage would have been left to the fifth member, the Army Corps of Engineers. It's not known how the federal agency was planning to vote. The rules need three votes to pass, though the commission had hoped for unanimous, bipartisan support. Environmentalists saw victory in the delay, claiming an erosion of support by the commission. However, Marcellus Shale Commission President Kath Kathryn Klaber said she remained hopeful that the commission would adopt "common-sense regulations aimed at responsibly developing clean-burning, job-creating American natural gas in the region." Fracking involves injecting water, sand and chemicals into a gas well to crack surrounding shale thousands of feet underground so trapped natural gas can flow into the well. Environmentalists fear it could result in contamination of drinking water supplies. Because of that fear, New York regulators are proposing to ban fracking in the New York City and Syracuse watersheds. New York state has had a moratorium on fracking since regulators started an extensive environmental review in 2008. The state is now holding hearings on proposed regulations, which, if approved, could allow drilling next year. New Jersey Gov. Chris Christie rejected legislation permanently banning fracking. The Democratic-controlled Legislature has not taken action on his recommendation for a one-year moratorium, though they may try to override the governor before recessing in mid-December. New Jersey has no Marcellus shale, so its interest in the issue revolves around water quality. Christie's office declined to comment Friday. The commission manages water use for the Delaware River Basin, and environmentalists say the drilling would threaten drinking water for 15 million people. The proposed rules would allow 300 natural gas wells in the Delaware River Basin, followed by a commission review before more are phased in. The eventual total could reach many thousands of wells. The New Jersey Sierra Club reported that there are 10,000 leases on hold in the basin that could move forward if the regulations are adopted. The National Park Service estimates 35,000 wells eventually could be constructed. Pennsylvania already allows drilling outside the watershed area. Environmental groups have gathered more than 73,000 signatures on a petition opposing drilling in the watershed.