According to reports, the former Prime Minister who took Britain into the conflict warned that the long-awaited hearings would become a "show trial" if they were held in public.

He is said to have communicated his view to his successor, Mr Brown, via the Cabinet Secretary, Sir Gus O'Donnell. He feared that a direct conversation would be leaked, The Observer claimed.

A spokesman for Mr Blair said: "This is a decision for the current Prime Minister, not the former one."

Mr Brown has faced severe criticism for announcing on Monday that the inquiry would be held behind closed doors and was forced into a partial climbdown days later.