Rod Blagojevich has given warning that he is preparing for a long and bitter fight against charges that he tried to “sell” Barack Obama's vacated Senate seat.

The embattled Governor of Illinois held a four-hour meeting on Saturday with Ed Genson, the Chicago defence lawyer who represented Lord Black of Crossharbour, the disgraced Daily Telegraph chairman, at his fraud trial last year.

The move raises the prospect of a protracted legal battle culminating in an ugly trial: Mr Genson, who successfully defended the R&B singer R. Kelly against child pornography charges, is a veteran who rarely takes cases that result in a guilty plea.

Lisa Madigan, the Illinois attorney-general, who has asked the state's highest court to declare Mr Blagojevich unfit for office, suggested that the Governor may step down as early as today. “We have heard that there is a possibility that he will make an announcement where he will step aside,” Ms Madigan, a political rival, told Meet the Press on NBC.

A spokesman, however, was quoted as saying there was “zero chance” that Mr Blagojevich's resignation was imminent.

The Governor is scheduled to sign a Bill today providing tax credits to film-makers in Illinois.

The “pay-to-play” scandal threatens to dog Mr Obama through the opening months of his administration and undermine his campaign message of change.

The President-elect has promised to release details of contacts between his staff and Mr Blagojevich's office about the open Senate seat but had not done so by last night.

Jesse Jackson Jr, who was co-chairman of Mr Obama's campaign, is due to meet prosecutors this week about allegations that his supporters offered to raise $1.5 million in campaign contributions for Mr Blagojevich in return for the Senate seat.

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