A man accused of being the fifth 21 July London bomber has admitted conspiracy to cause explosions.
Earlier this year, Manfo Kwaku Asiedu went on trial accused of conspiracy to murder. That charge has been dropped.
Asiedu, 34, who is also known as Sumaila Abu Bakari, faces a maximum life sentence for the charge.
Four other men have been convicted of conspiracy to murder over the failed 2005 bombings. They were jailed for life with a minimum of 40 years.
The Old Bailey heard that Asiedu - who faced a retrial next week - dumped a rucksack containing explosives in a west London park.
According to his counsel Asiedu, who is originally from Ghana, had opted out when he learned of the plan to kill.
A sixth man, Adel Yahya, pleaded guilty to a lesser charge earlier this week and was jailed for six years and nine months.
In the original trial, Asiedu contradicted the claims made by his co-conspirators who had maintained that the devices they carried were hoaxes. He said they were real explosive devices.
Asiedu, who is known by a variety of other names, came to the UK from Ghana on a false passport.
Having been brought up as a Muslim in his native country, he sought out local mosques where he could pray and help with voluntary work.
One of the first mosques he visited was in Finchley, north London, which was also frequented by co-defendant Yassin Omar.
In June 2005, after a fire in his flat, he moved in with Omar at Curtis House in New Southgate.
Curtis House was turned into a "bomb factory", with hundreds of bottles of hydrogen peroxide littering the flat.
Taking the stand during the trial, Asiedu presented himself as a terrified man and unwilling participant in the events of 21 July.
However, he was intimately involved in the buying of bomb ingredients including the critical element of hydrogen peroxide hair bleach.
He had been working as a painter and decorator at the time and told several wholesalers he needed the chemical to bleach wood or to strip wallpaper.
Deputy Assistant Commissioner Peter Clarke, head of the Met's counter-terrorism command, said: "Asiedu was one of the terrorists who wanted to bring a fresh wave of carnage to London on 21 July 2005 just two weeks after 52 members of the public had been killed by terrorists.
"Asiedu was a dedicated terrorist who has consistently lied about the role he played in this plot. Only now has he finally admitted his guilt."
He will be sentenced at Kingston Crown Court on 19 November.