The key witness in the prosecution of seven men accused of planning multiple bomb attacks on the UK has been branded a "liar" and "fantasist" in court.
Babar has been flown from prison in the US to give evidence
Mohammed Babar, 31, has told the Old Bailey that he plotted with the men to bomb bars, trains and shopping centres.
But Michel Massih QC, defending, told the witness he was a "well-schooled, well-rehearsed, well-trained liar".
The defendants, all from London and south-east England, deny conspiracy to cause explosions in 2003 and 2004.
Babar has pleaded guilty to terrorism-related offences in the US, and admits testifying in the Old Bailey trial in the hope of getting a reduced sentence.
Mr Massih told him: "You are a liar, nothing more than a conceited fantasist."
The lawyer also pointed out Babar had not taken the oath on the Koran.
"You, Mr Babar, are an accomplished liar, frightened of the flames of hell," said Mr Massih, who is representing one of the defendants, Waheed Mahmood.
Babar denied making up his claims. The Pakistan-born US citizen has immunity from prosecution in the UK.
Waheed Mahmood, 34, Jawad Akbar, 22, Omar Khyam, 24, and his brother Shujah Mahmood, 19, all of Crawley, West Sussex, each deny a charge of conspiracy to cause explosions between January 2003 and March 2004.
Denying the same charge are Salahuddin Amin, 31, from Luton, 23-year-old Anthony Garcia - also known as Rahman Adam - of Ilford, east London, and Nabeel Hussain, 20, of Horley, Surrey.
Mr Khyam, Mr Garcia and Mr Hussain each deny possessing ammonium nitrate fertiliser - a chemical that can be used in bomb-making.
Mr Khyam and Shujah Mahmood deny possessing aluminium powder, also used in bomb-making.
The trial continues.