WASHINGTON (CNN) -- The Bush administration's environmental policies came under fire Monday from two Republican governors, who spelled out their criticism in an opinion column published in The Washington Post.

California Gov. Arnold Schwarzenegger and Connecticut Gov. Jodi Rell took aim at the Environmental Protection Agency in the joint op-ed calling this executive order issued by President Bush last week, "more of the same inaction and denial."

The two governors have been leading efforts to enact tailpipe emission standards, which they claim are stronger than current federal requirements and would dramatically cut down on the greenhouse gases released by cars.

:Enacting these standards would be a huge step forward in our efforts to clean the environment and would show the rest of the world that our nation is serious about fighting global warming," the two governors wrote. "Yet for the past 16 months, the Environmental Protection Agency has refused to give us permission to do so."

EPA deputy press secretary Jessica Emond responded with a press release.

"EPA initiated the statutory process for reviewing California's waiver request used for all waivers, and the agency must complete that process before making a decision. By the end of this month, the agency will hold two public hearings, one in Washington, D.C. and a second in Sacramento, Calif."

However, the governors remain skeptical of the EPA's sincerity.

"We are far from convinced that the agency intends to follow the law and grant us our waiver," Schwarzenegger and Rell wrote. "If it fails to do so, we have an obligation to take legal action and settle this issue once and for all."

-- CNN Producer Joshua Rubin