Tree experts have warned it is just a matter of time before a deadly disease which is sweeping the country hits Hampstead Heath.

A team of a dozen rangers and arboriculturalists are combing the capital’s largest open space inspecting clumps of trees and hedges for signs of ash dieback disease.

A summit was held in London yesterday to discuss a strategy to control the deadly fungal which is threatening to kill 80million ash trees across the country.

Jonathan Meares, the Heath’s tree manager, said it was a question of “when rather than if” the disease struck the Heath, and warned that Britain was bracing itself for disaster similar to when Dutch Elm disease wiped out up to 30million trees in the 1970s.

Mr Meares told the Hampstead Heath Consultative Committee on Tuesday night (November 6): “Just to reassure people we are just starting a survey of existing ash trees on the Heath.

“There is no immediate sense of anything happening or the disease manifesting but we need to do a more thorough survey.

“It’s when rather than if, but hopefully they (the trees) will weather the storm.”

Heath superintendent Simon Lee admitted “it’s not looking good”.

The inspection will begin by monitoring the Heath’s largest collection of ash trees in Dukes Field next to the bandstand and on the Heath Extension near Hampstead Garden Suburb.

The team will examine the trees for any symptoms of the airborne disease.

If a tree is infected, its leaves will turn brown then black, before the stem of the branch becomes discoloured.

The fungus then works its way into the trunk of the tree and can cause it to die.

If the Heath’s rangers find any symptoms, samples will be collected and sent to a laboratory for testing.

Mr Meares added: “Next week we will have a better idea whether we have the disease on site.”

The University of East Anglia has set up a website and is calling on the public to send in sightings of the disease.

There have been unconfirmed sightings of the fungus growing on trees near the Model Boating Pond on the Heath and at two other sightings in Muswell Hill, according to the site.