Emergency measures to prevent the UK's ash trees being wiped out by a fungal disease have been discussed at a high-level meeting of ministers, experts and officials.
Environment Secretary Owen Paterson convened a Government Cobra crisis committee meeting to examine the latest developments and co-ordinate action to halt its spread.
After the meeting, he said a mass survey of trees in almost 3,000 test areas should produce a clear picture of the extent of the threat by the middle of next week.
The Government's chief scientific adviser briefed the hour-long Whitehall meeting, which included officials from the Forestry Commission and the devolved administrations.
Mr Paterson said: "We have had an assessment of the state of the disease. We also had an assessment of the current survey, where we are looking at 2,900 10km squares right across the United Kingdom.
"This was a meeting that brought in the devolved administrations in Scotland, Wales and Northern Ireland showing that, right across the UK, we are determined to work together.
"We also had a presentation on possible solutions - at the moment we do not have a cure for the disease - and also measures we might take having established the survey, which should be completed by the middle of next week."
The disease, which causes leaf loss and crown dieback and can lead to ash tree death, has wiped out up to 90% of ash trees in some areas of Denmark and has now been found in Britain.
The Government banned imports of ash trees on Monday after a programme that has seen 100,000 specimens destroyed since the disease was discovered in March. But the discovery of the disease in mature trees in East Anglia has raised fears it has blown in to the UK as well as arriving on imports and will be hard to control.
Experts are concerned ash trees could face the same fate as the elm, which was devastated by Dutch elm disease in the 1970s. It could have a dramatic impact on wildlife and lead to rare species being lost if it takes hold.