Hillary Clinton to make her millions on the speaking circuit

She is under intense pressure from Democratic allies to run for the party's presidential nomination in 2016, having been defeated by Mr Obama in a hard-fought contest in 2008.

Having spent four years on a gruelling schedule, which included almost 90 full days on flights, she has repeatedly brushed off suggestions that she is already hatching plans for one last political campaign.

Yet speculation has continued to mount, amid the disclosure that Mr Obama's political operation has paid off Mrs Clinton's remaining quarter-million-dollar debt from 2008. A group of supporters has founded "Ready for Hillary", a fundraising group poised to assist any official campaign.

She and Mr Clinton, who have homes in Washington and Chappaqua, New York, are believed to be seeking a summer property in The Hamptons, the exclusive coastal community outside New York City.

Earnings from her new job, in which she is also expected to give speeches for free to assist charities, may help cover the cost in an area where properties sell for an average of $2 million.

Even former president George W Bush, who became notorious for his garbled syntax, is believed to have commanded between $100,000 and $150,000 per speech since leaving office in 2009.