Confor’s appeal comes as the disease was confirmed in Kentish and Essex woodland yesterday.

Confor chief executive Stuart Goodall said the commission faced a big task of surveying sites where diseased ash saplings have been planted.

“This amounts to several thousand sites and the Forestry Commission, which has suffered cuts of 25%, is struggling to achieve this before the autumn leaf fall,” he said.

The Forestry Commission said the latest confirmed cases in Kent and Essex, affecting mature trees, were likely to have been caused by wind-blown spores from mainland Europe.

The disease has now been confirmed in 14 tree nurseries, 26 planting sites and 32 locations in forests and woodlands. Plant health experts are urgently checking 220 prioritised sites which have received saplings from nurseries where Chalara was discovered.

About 2,500 other blocks of land where mature ash trees are known to be present are also being checked.

“I would expect even more cases to be confirmed as our urgent survey of ash trees continues,” said environment minister Owen Paterson.

Survey results will be presented to an emergency summit on tree and plant health later this week. Confor has welcomed the announcement of the summit.

Meanwhile, Zac Goldsmith MP and the Countryside Restoration Trust have tabled an Early Day Motion calling on the government to set up a Tree Protection Task Force.