The political drama over whether Hillary Clinton will secure the position of US Secretary of State in the new Barack Obama administration intensified yesterday as negotiations between the Clinton and Obama camps threatened to sour.

All the indications are that Mrs Clinton desperately wants the job as America's top diplomat. Ever since it became clear last week that she was originally being offered a minor role in the Senate in helping to organise the reform of US healthcare, Mrs Clinton has been on the hunt for a "legacy" job.

But in scenes more worthy of divorce proceedings than an appointment to a plum job at the top of the State Department, the vetting of Bill Clinton – which Obama insiders are calling "the project" – is being handled by an inner coterie of lawyers and trusted advisers from both sides.

The sticking point in the negotiations is the ethical review of former President Clinton's most confidential dealings. So sensitive is the vetting of his overseas business and charitable dealings – especially the controversial details of his foreign donors – that the Clintons are using lawyers to keep things mum under lawyer-client privilege. But the bigger political issue is the perception in some quarters of the Obama camp that the Clintons have the potential to create a rival centre of power, and, in the light of his wide circle of foreign connections, cast a shadow over Mr Obama's foreign policy.

In what some accounts described as "concessions" to help his wife get the job, Mr Clinton has offered to disclose the identities of all future donors to his charitable activities, and those who contributed more than $1m in the past. "I'll do whatever they want," he said on Wednesday when asked at a public ceremony about the vetting process.

Much of the ugliness of the primary campaign focused on which of the two was best equipped to lead America in a hostile world. Mr Obama dismissed the woman he now wants as his top diplomat as a glad-handing First Lady who had tea with ambassadors and enjoyed red carpet hospitality in 83 foreign countries. Mrs Clinton, in turn, ridiculed her former rival's readiness to be commander in chief, saying it all rested on "a speech he made in 2002".

A political Kabuki dance is now underway in the pages of newspapers as each side in the drama manoeuvres to protect itself should the talks collapse and the appointment fall through. There is a legacy of bad blood between the two former presidential rivals and the strict vetting process has stirred up some bad feelings that had been put away in the final stages of the election campaign.

The complications of dealing with the Clintons were never so clear as on 16 November when the former president said his wife had potential to be "really great as a Secretary of State". The trouble is that he made his remarks while being paid by the National Bank of Kuwait to give a speech. He pulled in more than $10m doing this sort of thing last year, and the prospect of subjecting his talks to the strictest standards of State Department vetting will be galling.

Then there are the donations to his charitable efforts and the still secret donors to his presidential library, some of them from foreign powers that a US Secretary of State is bound to be butting heads with in the future.

Mr Clinton told the Chronicle of Philanthropy in September: "The only reason I didn't want to [disclose] the library donors is that no previous president has. I suppose if Hillary were elected president, or maybe even if she had been nominated, we would have had to go back to the donors and at least disclose everyone that didn't object to it. But I wouldn't have any objection to it."

But just as worrisome would be Bill Clinton's ongoing relationships with world leaders and his predilection for offering advice – as he did in 2006 when Dubai sought help in a controversial attempt to acquire six terminals in US ports. (Hillary, a leader in the effort to block the deal that she called an "unacceptable risk" to national security, later said she was unaware that Bill had been coaching the other side.)

Mr Obama's steadiness has been revealed by the long-term view he is taking. Unlike every other recent president he is holding out the prospect of appointing his greatest rival to the most important job in his cabinet.

As Senator Claire McCaskill said of those Obama supporters angry that a plum appointment could go to a bitter rival – they need to accept that the President-elect's willingness to work with those he has clashed with is a reason so many people voted for him.