Attorney general Lord Goldsmith has said he will have an input on whether anyone is charged in connection with the cash-for-honours affair.
Lord Goldsmith, a close friend of prime minister Tony Blair, said this morning that "sensitive and complex cases" such as the cash-for-honour investigation were usually put before his office.
On Friday, the Metropolitan police handed its file on the matter to the Crown Prosecution Service, which is expected to decide on the basis of the Scotland Yard probe whether sufficient evidence exists to press charges against the chief suspects.
But Britain's top lawyer says he too will have a role to play.
"I can assure you and everyone else that, if I am consulted, any decision will be taken objectively, on the evidence, independently of government, because my first duty is to the law, not to party politics," Lord Goldsmith told Sky News this morning.
"My office will appoint independent counsel. I will consult the opposition parties on the identity of that person and make public the advice that is given if there is not a prosecution," he added.
Reports emerged yesterday citing senior police officers alleging the file contained claims of "serious wrongdoing", but these have not been verified.
And this morning the Times newspaper suggested that Mr Blair's chief of staff, Jonathan Powell, may also face charges over attempts to cover up police investigating the probe.
Parliamentary aide Ruth Turner and city academies advisor Des Smith have been arrested and released on bail in connection with the probe, which widened in recent months to include a potential cover-up.
Lord Levy, a Labour fundraiser who was made a peer shortly after making a sizeable donation to the party's coffers, has been arrested and released twice.
All three deny any wrongdoing.
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