A Oklahoma state senator says that he was concerned about an email he received from a local Tea Party leader pushing him to support legislation to block Agenda 21, so much so that he turned the email over to the Oklahoma State Bureau of Investigations.

Republican state Sen. Cliff Branan asked the OSBI to investigate an email he received from Al Gerhart, the co-founder of the Sooner Tea Party, that strongly urged Branan to back legislation that would prevent the U.N.’s Agenda 21 from being implemented in the state.

Agenda 21 is a non-binding U.N. agreement aimed at promoting sustainable development, though right-wing conspiracy theorists believe it is “a really nice way of saying ‘centralized control over all of human life on planet Earth,’” as Glenn Beck has put it.

A number of states have considered and advanced legislation to block Agenda 21, and an Oklahoma state senator introduced a bill in December to do the same. The bill is now heading to the Senate Energy and Environment Committee, which Branan chairs.

In a March 26 email to Branan, Gerhart wrote: “Get that bill heard or I will make sure you regret not doing it. I will make you the laughing stock of the Senate if I don’t hear that this bill will be heard and passed. We will dig into your past, yoru family, your associates and once we start on you there will be no end to it. This is a promise.”

More: Oklahoma Tea Partyer Threatens Legislator Over Agenda 21