In what will be seen as a huge blow to Scotland Yard,  the long-running investigation, which has been funded entirely by the taxpayer, is set to draw to a close with no charges brought against Tony Blair's inner circle.

Angus MacNeil, the MP whose complaint sparked the investigation, said: “I think it’s quite extraordinary if this is the case. That the news has come out in this way, leaked by the CPS.”

He continued: “It seems strange to me that the CPS has sustained this investigation and encouraged the police to carry on, then to say it has been a wild goose chase.

“Regardless of that, I think it has changed the political climate in the UK.”

The investigation into the cash for honours scandal centered around Tony Blair's close personal friend Lord Levy, and saw the former Prime Minister being called in for questioning as a witness.