One of the 21 July bombing suspects planned "bigger and better" attacks than those on 7 July, a jury has heard.
Mr Ibrahim and Ramzi Mohammed were arrested after a police raid
The lawyer of a fellow defendant said Muktar Ibrahim wanted to explode four bombs on the Tube and destroy a London tower block with a booby-trap device.
Stephen Kamlish QC told Woolwich Crown Court that Mr Ibrahim had wanted the flats to go up in "a ball of flames" - a claim he denied.
He is one of six men who deny conspiracy to murder in July 2005.
They also deny conspiracy to cause explosions on the transport network on 21 July 2005 - two weeks after the 7 July attacks in which four suicide bombers killed 52 people.
Mr Kamlish, representing Manfo Asiedu, said to Mr Ibrahim: "You wanted to do a copycat of 7/7 - four bombs on 7/7, four bombs two weeks later on 21/7. That was your plan.
"We say your 21/7 bombs were to be bigger and better in your twisted thinking than that of 7/7.
"Four real bombs on the Tube and one block of flats, a tower, destroyed, going up in a ball of flames. That was your plan, wasn't it?"
Mr Ibrahim denied that and said, as a Muslim, he believed those who committed murder would go to "hell fire".
He maintains he planned to create a "fake explosive", in a demonstration against the Iraq war, that would cause panic but not hurt anybody.
Mr Kamlish said the plan to blow up the tower block at Curtis House, New Southgate, north London, involved a sideboard with trigger wires intended to spark an explosion when police entered the premises.
The sideboard was allegedly covered in an explosive charge
Jurors were shown the sideboard, which they were told had been covered in a charge and if detonated would have destroyed the tower block.
Asked why there was a hydrogen peroxide and chappati flour mixture on the furniture - the substances found in the Tube devices - Mr Ibrahim said it could have got there when he was testing the explosives.
He also said he did not know why wires were scattered over the floor.
Mr Kamlish told the court that Mr Ibrahim, who called himself "emir" (meaning "prince"), had "ordered" Mr Asiedu to take part in the 21 July attacks at the last minute because he was too afraid to die himself.
"You actually decided that you couldn't kill yourself for any particular cause; therefore you had to find a fourth person to carry out the fourth bomb," he said.
On the day of the alleged attacks, however, Mr Asiedu dumped his device in west London, said Mr Kamlish.
He then returned to Curtis House where he discovered the booby-trap and dismantled it, Mr Kamlish added.
"I do not know why Asiedu is making these accusations," Mr Ibrahim told the court in a day which saw a number of heated exchanges between him and the barrister.
Mr Ibrahim told the court he thought the 7 July bombings had been "a success" because it got the government and the public talking about Iraq and Afghanistan, but added it was "unfortunate" people had died.
The jury also heard that Mr Ibrahim served just over three years in jail for two robberies, to which he pleaded guilty, and was a convicted sex offender.
In 1995 he robbed a 77-year-old woman and was part of a gang which punched and kicked a man during another robbery.
Two years earlier, he indecently assaulted a girl in an alleyway. He pleaded guilty and was given a one-year supervision order.
Mr Ibrahim is on trial with Yassin Omar, 26, from New Southgate, north London; Mr Asiedu, 33, of no fixed address; Hussein Osman, 28, of no fixed address; Ramzi Mohammed, 25, of North Kensington, west London; and Adel Yahya, 24, of High Road, Tottenham, north London.