George Osborne was offered help with his maths skills after a BBC comedy stunt show infiltrated his speech to bankers.
The Chancellor was presented with a GCSE Maths exercise book as he prepared to reveal plans for an emergency bank funding scheme at a Mansion House event, in central London, last night.
Mr Osborne was handed the book by Heydon Prowse, who is filming a new comedy series for BBC3 with collaborator Jolyon Rubinstein.
The programme, which has two working titles; We Know Where You Live and The Revolution Will Be Televised, will be shown later this year.
A BBC spokeswoman said the show was a "topical, satirical, entertainment series that challenges the establishment".
Prowse - who hit the headlines in 2009 after covertly filming Conservative politician Alan Duncan saying MPs had been "nationalised" - and Rubinstein became internet hits with their satirical work for Don't Panic Online.
It is understood Prowse was allowed into the event after he provided a false name and claimed he was filming a current affairs show.
Wearing a black suit and bow tie, he tried to present Mr Osborne with a spiral-bound book labelled GCSE Maths Exercise Book as the Chancellor took part in the entry procession with the Lord Mayor of London.
Witnesses said Prowse was pulled away from Mr Osborne by a press officer. Another man - believed to have been Rubinstein - then began arguing as part of the stunt before they were both escorted off site.
Bank of England governor Sir Mervyn King and his wife were walking behind Mr Osborne at the time of the incident, witnesses said.
A cameraman who filmed the stunt later told photographers they were making a comedy TV show from Hat Trick productions.