Specialist tree surgeons are installing slow release chemicals to encourage the roots to grow. They will also use a crane to remove a number of the heavier limbs to prevent the tree from falling or blowing over.
More top news
They said they wouldn't do it. But the Met Police couldn't resist the challenge set by their colleagues in Scotland.
The results of the first preference votes counted so far gives an early indication that Mr Khan is line to take power at City Hall.
Mr Goldsmith's campaign, run by Sir Lynton's communications firm has come under fire from Labour.