Brent crude was down 53 cents, or 0.7 pc, at $71.47 a barrel by 1:25 p.m. EDT (1725 GMT). U.S. West Texas Intermediate oil declined 35 cents to $68.01 a barrel, snapping a three day rally.
Lopez Obrador, a self-styled anti-graft crusader, said the public consultation would strengthen participatory democracy, but critics saw it as little more than a political stunt