Commodity Futures Trading Commissioner (CFTC) Bart Chilton, a major proponent of speculative position limits, announced that Tuesday’s meeting will be his last at the agency.

“This is a significant day for me…The first reason is that, at last, we are considering what I believe to be the signal rule of my tenure here at the Commission. I’ve been working on speculative position limits since 2008. The second reason today is noteworthy is that this will be my last Dodd-Frank meeting,” Chilton said during the CFTC meeting. The proposed position limit regulations will be “unassailable in court, good for markets and good for consumers,” he said (see separate story).

“Early this morning, I sent a letter to the president expressing my intent to leave the agency in the near future. I’ve waited until now — today — to get this proposed rule out the door, and now — at last — with the process coming nearly full circle, I can leave. It’s with incredible excitement and enthusiasm that I look forward to being able to move on to other endeavors.”

The ranks may thin even further at the CFTC. Speculation has been rampant that CFTC Chairman Gary Gensler may leave the Commission at the end of the year. Jill Sommers, one of two Republicans on the Commission, left the CFTC in March.

With the planned departure of Chilton and possible exit of Gensler (both Democrats), the Commission would be down to two members: Commissioner Scott O’Malia, a Republican; and Commissioner Mark Wetjen, a Democrat.

Chilton was nominated by President Bush and confirmed by the Senate in 2007. In 2009, he was re-nominated by President Obama and reconfirmed by the Senate. He has served as the chairman of the CFTC’s Energy and Environmental Markets Advisory Committee. His career spans 25 years in government service. He has worked on Capitol Hill in the House of Representatives, in the Senate, and served in the executive branch during the Clinton, Bush and Obama administrations.

He authored a book — Ponzimonium: How Scam Artists are Ripping Off America — in which he detailed 10 Ponzi scams that took place in 2009.