Aircraft almost lost an engine in volcanic ash

A Thomas Cook Pilot had to divert back to Manchester airport shortly after take off. The B767 which took off from the the Manchester airport after the ban on airspace was revoked, suffered in the volcanic ash and was safely landed. It seems that there were no passengers on board the flight. The pilot reported that he smelt ash and a bad running engine when the aircraft was at 20,000 ft climbing to 39,000 ft its cruising altitude. Experts fear that the volcanic ash might have clogged the engine values.When asked by the ATC if the pilot wanted to declare an emergency, the pilot had not declared an emergency instead requested priority for landing without being put on holding pattern.