Khan warned that the proposed cuts would lead to the loss of thousands of community police officers who "act as the eyes and ears of the security services, providing the intelligence and information that allows us to disrupt attempted terrorist attacks".
Assistant Commissioner Mark Rowley said Butt was known to police and MI5, but because the probe into him did not reveal evidence of attack planning or other serious offending he was prioritised accordingly.
He also used the name Rachid Elkhdar, and claimed to be six years younger.
His accomplice, Rachid Redouane, 30, was not known to authorities. "He has more important things to do than respond to Donald Trump's ill-informed tweet that deliberately takes out of context his remarks urging Londoners not to be alarmed when they saw more police - including armed officers - on the streets", the spokesman had said.
General Election: Labour continuing to close gap on Tories new poll shows
When she's been given interviews with experienced political journalists, she struggled to answer unscripted questions. May had said she was too busy "thinking about Brexit negotiations" and "meeting voters" to take part in the debate.
Also, at least 20 others have been injured in the attack which comes less than two weeks after 22 people were killed and scores were injured by a suicide bomber at an Ariana Grande concert in the northern English city of Manchester.
Josh Dell contributed to this article. The identities of the assailants have not yet been disclosed for fear of compromising the investigation, though police said they know their names. The campaign roared back into public view Monday after a one-day hiatus, with Prime Minister Theresa May and Labour Party leader Jeremy Corbyn trading blame over one another's security stances.
Her devastated family described the vivacious woman as a devoted daughter and sister.
"Whatever the United States can do to help out in London and the U.K., we will be there", Trump wrote.
The Labour mayor also warned that London would be more risky under Conservative government budget cuts, which could lead to 12,000 fewer police officers.
Microsoft launches Face Swap app for Android devices
You also could choose to use Face Swap for a more practical application, such as possible hair cut changes or hair color changes. It is also capable of finding faces in images and placing your swap as well as placing multiple faces in a single scene.
Twenty-one of the 48 people injured in the attack remained in critical condition late Sunday.
He is said to be inconsolable and family members are rushing to his side.
He is the second victim to be named after Canadian woman Christine Archibald who died on London Bridge.
A vigil was held at Potters Field Park by the River Thames on Monday evening to remember the victims.
She said: "While our pain will never diminish, it is important for us all to carry on with our lives in direct opposition to those who wish to destroy us". "If you know Tyler, please be there for him now, and later when what happened sinks in, he's going to need us all".
Wawrinka, Murray, Halep in action in 4th round in Paris
Women's 4th rd: Elina Svitolina (Ukr) bt Petra Martic (Cro) 4-6 6-3 7-5, Simona Halep (Rom) bt Carla Suarez Navarro (Esp) 6-1 6-1. Marin Cilic completed the quarter-final line-up when South Africa's Kevin Anderson retired with a thigh injury trailing 6-3, 3-0.
The Islamic State terror group, also known as Daesh, has claimed responsibility for the London Bridge rampage, while the attack has sparked fears Britain is in the grip of a spate of copycat incidents. "We're calling for a restoration of police numbers, and there's a call being made for her to go, because of what she's done on the police numbers".
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