The youngest of Saturday's attackers is said to have told Italian authorities "I'm going to be a terrorist", while officers reportedly found Islamic State-related material on his mobile phone when they intercepted him.
London's Metropolitan Police have released the names of the perpetrators of Saturday evening's terrorist attack, as polls show the U.K.'s governing party is losing ground in Thursday's general election.
"However, there was no intelligence to suggest that this attack was being planned and the investigation had been prioritized accordingly", police said in a statement.
Most of the London Underground stations reopened yesterday in the neighbourhood where the attack took place, allowing normal life and commerce to resume after more than 24 hours of lockdown. He also appeared in a Channel 4 TV documentary called The Jihadis Next Door, where he openly espoused allegiance to ISIS.
The announcement came a day after London's Metropolitan Police Service named two other men as attackers: 27-year-old Khuram Sharzad Butt, a British citizen born in Pakistan, and 30-year-old Rachid Redouane, who "claimed to be Moroccan and Libyan".
Police have arrested three people on terror charges, but they have said they are not linked to the London Bridge attack.
Seven people were killed and dozens wounded in the rampage.
Police shot and killed the three attackers, who were wearing suicide vests that turned out to be fakes.