Environment Secretary Owen Paterson is heading a summit meeting of tree experts in London on Wednesday for the latest stage in the crisis fight against the ash dieback disease.
Downing Street said he was holding meetings twice daily to discuss the problem with experts - and he even convened a Cobra crisis committee on Friday to examine the latest developments.
Meanwhile a Lincolnshire plant nursery forced to destroy 50,000 ash trees said today it was suing the government for failing to block imports of the ash tree sooner.
Horncastle's Crowders Nurseries managing director Simon Ellis said the Horticultural Trades Association wrote to ministers in 2009 warning of a new virulent strain of the disease and calling for British borders to be closed.
The Department for Environment, Food and Rural Affairs reported 52 confirmed cases.
Imports of ash trees were banned last week, while 100,000 trees have been destroyed since the disease was discovered in March.
Mr Ellis told BBC Radio 4's Today programme: "They should have taken it seriously at the time.
"They chose not to and now we have this really dramatic situation and unfortunately, by the sound of it, the ash tree disease has spread throughout the UK."
The fungal disease is threatening to wipe out most of Britain's ash trees. It has already killed up to 90 per cent of ash trees in some areas of Denmark.
Asked if compensation would be paid to anyone who has lost out because of failings in the official response, Prime Minister David Cameron's official spokesman said: "If people are going to claim compensation that would be an issue which would be dealt with ultimately by the courts."