Ertel, 40, heads Evolution Markets, which sells chits that companies use to offset their emissions of air pollutants.

FORBES: Selling the Blue Sky

Mr Edwards has the means to disappear, they say: call in the last of his chits and escape to a desert island.

ECONOMIST: Louisiana politics

Obama should be calling in chits and twisting arms in all possible directions, beefing up U.S. penalties on those who help Iran's regime, and urgently rallying a coalition to do the same.

CENTERFORSECURITYPOLICY: Flirting with disaster

Even then it is also highly likely it becomes a slimmed down beast - with the Treasury simply handing departments one year spending chits to tide them over to the other side of an election.

BBC: A tough end to a tough week for Nick Clegg