It has killed 90 per cent of the Netherlands' ash trees in just seven years. Now conservationists are desperately trying to stop the devastating Chalara fraxinea fungus from spreading throughout Britain's woodlands by calling for a ban on ash being imported into the country.
With various species of ash forming almost a third of the UK's forests, the disease – commonly known as "ash dieback" – could have a particularly devastating impact on the countryside.
Having been spotted here for the first time in June, the fungus has now been seen in 10 locations and is worrying the Woodland Trust so greatly that it has warned it could become a latter-day version of Dutch elm disease.
Dutch elm disease killed more than 20m of Britain's elms after its arrival in the 1960s.
Pleading for a compulsory ban on ash trees being brought into the UK from Europe, where it is now well established, Norman Starks, UK operations director at the Woodland Trust, said: "This is not the time for weak, ineffective, voluntary embargoes; we are calling on governments across the UK to put in place an immediate and compulsory ban on imported ash before it's too late."
He warned that there are already British trees being blighted by diseases spreading from imported plants, citing Phytophthora ramorum "which is wiping out larch trees". He added: "As an island, we have a great opportunity to stop the spread to the UK by closing our borders to this disease. If the disease takes hold, the cost and safety implications regarding the removal of infected ash trees would be huge."