ALBANY – With one natural-gas pipeline effectively rejected and another pulled off the table last week, anti-pipeline activists are flexing their political muscle in New York.

The activists, many of them opponents of hydraulic fracturing for natural gas, are pointing to the state Department of Environmental Conservation’s Friday rejection of a key permit for the proposed Constitution Pipeline as a symbol of their collective might.

But the investors behind the proposed pipeline vowed Monday to fight the DEC’s decision, accusing the state of "flagrant misstatements” and hinting at what is likely to be an eventual court battle.

The Constitution investors, led by energy-infrastructure company Williams Partners, issued a statement Monday saying they will "pursue all available options" to overturn the state DEC's decision Friday, which effectively blocked the pipeline from moving ahead in New York.

The proposed 124-mile pipeline would carry natural gas from northeast Pennsylvania fracking fields to Schoharie County, cutting across eastern Broome, Delaware and Chenango counties along the way.

“In spite of NYSDEC’s unprecedented decision, we remain absolutely committed to building this important energy infrastructure project, which will create an important connection between consumers and reliable supplies of clean, affordable natural gas," the investors wrote in a joint statement. "We believe NYSDEC’s stated rationale for the denial includes flagrant misstatements and inaccurate allegations, and appears to be driven more by New York State politics than by environmental science."

The DEC denied a water-quality permit application from the Constitution investors, raising concerns about the pipeline's impact on various waterways and accusing the company of withholding detailed plans the state was seeking.

The decision came just days after Kinder Morgan, a Houston-based company, scrapped plans to build a natural-gas pipeline connecting the Albany area to Massachusetts.

In a letter to the Constitution Pipeline backers, DEC Chief Permit Administrator John Ferguson said the state agency had requested site-specific plans that showed how deep the 30-inch pipeline would be at each of the 251 streams the pipeline would cross.

The agency never received that analysis, Ferguson wrote.

The Constitution investors pushed back Monday, saying they "did not refuse to provide a comprehensive analysis of pipe depth."

"Completely contrary to NYSDEC’s assertion, we provided detailed drawings and profiles for every stream crossing in New York, including showing depth of pipe," the company wrote.

In a statement Monday, DEC spokesman Sean Mahar said the agency's letter "outlined a number of failures of the applicant to present adequate information for the state to determine New York’s water quality standards would be met."

Those opposed to the pipeline included a network of opponents of large-scale hydraulic fracturing, the technique paired with natural-gas drilling that Gov. Andrew Cuomo's administration banned in late 2014.

Walter Hang, an Ithaca-based organizer who helped lead anti-fracking activists who called in and emailed their pipeline concerns to the Cuomo administration, said his goal is to stop any and all expansion of fossil fuels in New York.

"New York now has literally thousands of highly experienced grassroots fractivists who take highly effective political action in their own communities as well as throughout the state as part of extensive anti-fracking and pipeline opposition campaigns," Hang said. "This organized force has successfully focused intense pressure on Governor Cuomo and is growing stronger with each hard-fought victory."

Some, now, are focusing their efforts on other pipeline projects, including the Algonquin natural-gas pipeline project that cuts through Westchester and Rockland counties.

The project is already underway in New York and three other states, and the Cuomo administration’s bid to halt construction in New York was rejected by the Federal Energy Regulatory Commission last month.

In a letter sent earlier this month to FERC Secretary Kimberly Bose, 38 state lawmakers asked the federal commission to halt construction of the pipeline so the state can complete a safety analysis of the project and its proximity to the Indian Point nuclear power plant in Buchanan, Westchester County.

“We demand that FERC respect New York’s authority and jurisdiction in this matter and stop construction of the (Algonquin) project immediately until the State’s independent safety analysis is completed,” reads the letter, which was organized by Assemblywoman Sandra Galef, D-Ossining, and Sen. Tony Avella, D-Queens.