Ash tree crisis

One of London's most popular trees is under serious threat.

A fungal disease is wiping out ash trees across the country, and now there's a warning that it could spread to the capital.

The die back disease has already been spotted in Surrey and the chances of it spreading to trees in and around London is a real possibility.

And this is not the first time a species of tree has been threatened with near extinction.

The Elm was once as common and iconic as the ash - it was virtually wiped out by Dutch Elm Disease.

The Forestry Commission has now declared a national emergency and the government has banned all imports and movements of ash trees.

Scientists are not entirely sure how the disease spreads but it's believed to be airborne - carried by rain, wind and even insects.

The Ash is the UK's third most common tree - there are more than 80 million of them. If it goes, it will change the landscape not just of the countryside - but also of the capital forever.