When a government agency initiates a policy that will affect literally every American family and business, that agency should consider all stakeholders’ opinions in a serious, balanced way. It is absolutely inappropriate for one outside organization to have completely dominant influence on that regulatory process. That is simply not how our federal government was intended to operate.

But that’s exactly what the EPA allowed in developing its existing source performance standards, the centerpiece of its war on coal and other traditional energy. What’s worse, the EPA clearly tried to hide this from the public — until we called them on it.

This week, Republicans on our oversight committee released a series of documents that show just how the Natural Resources Defense Council (the NRDC) played a wildly oversized role in developing President Obama’s proposed carbon plan. The NRDC is a far-left environmental group that uses an extremely well-funded litigation and lobbying strategy to force climate polices on the U.S.

Let me break down how this happened.

In 2010, the NRDC and its lawyers and lobbyists sued the EPA to initiate new regulations on greenhouse gas emissions. While this might seem a hostile act toward EPA on its face, it was exactly the opposite — a coordinated strategy.

This kabuki dance then allowed the two supposedly opposing sides of the suit — in reality close allies — to settle behind closed doors on December 23, 2010. Practically all of the impacted parties were excluded from the discussions leading up to the settlement. This tactic is commonly referred to as “sue-and-settle.”

As a recovering lawyer, I can tell you that in a normal lawsuit, one if not both sides walk away from the courthouse upset. But in this case, the NRDC and the EPA literally congratulated each other gleefully. In an email uncovered by our committee, EPA Administrator Gina McCarthy wrote to NRDC’s climate policy director, David Doniger: “I really appreciate your support and your patience … . The success is yours as much as it is mine.”

Following the settlement agreement, the NRDC then gave McCarthy and the EPA its carefully drafted proposal to regulate carbon dioxide at existing power plants and to force the entire country into costly compliance. In a June 2011 email exchange, Doninger wrote to Gina McCarthy: “Nice to bump into you yesterday. Here is the presentation we gave to the work group. I want to draw your attention especially to option 2 for existing sources.”

Gina McCarthy’s response: “Let me take a quick look. I would never say no to a meeting with you.”

Sounds like quite a date.

For more details on these damning emails, just go to our committee website at epw.senate.gov.

From then on, the EPA practically cut and pasted the NRDC’s proposed carbon plan and made it their own. Perhaps the only part of it that truly originated with the EPA was the EPA’s logo inserted on the cover page. Even observers at reliably left-wing outlets like the New York Times have since reported on this unprecedented NRDC role.

When it comes to a major new regulation — especially one that would have devastating economic impacts — there must be an open and honest conversation between the government and the public, including outside organizations and impacted parties. But in this case, only the EPA and the NRDC were truly engaged — leading to a court agreement to regulate the entire U.S. economy. No other voices were heard.

Those at the EPA want you believe they created this rule on their own. They want you to believe that they didn’t start working on the rule until President Obama publicly asked them to do so in June 2013. They want you to believe that the public got an equal opportunity to provide feedback starting in June 2014. But none of that is true.

The carbon rule they’ve concocted will permanently stymie our economy, limit growth, and kill hundreds of thousands of jobs across the country. It will decrease electricity reliability and deal a crushing blow to low-income families and senior citizens as energy poverty becomes the new normal, just as it is in Europe.

And now the voluminous emails and other documents we’ve uncovered clearly demonstrate the EPA and the NRDC’s beyond-cozy relationship that was behind it all.

You have to ask yourself, with regard to the EPA and the NRDC: So who is working for whom? Even more importantly, is anyone in this beyond-cozy conspiracy working for the American people?

David Vitter is the top Republican of the U.S. Senate Environment and Public Works Committee.