Telescope technology that allowed Cambridge University astronomers to take sharper pictures than the Hubble space telescope has failed to attract the British funding needed for its next step.
Foreign collaborators are being sought to keep alive plans for a £15 million-£20 million successor to the Cambridge Optical Aperture Synthesis Telescope (Coast).
The Particle Physics and Astronomy Research Council, which currently funds the Coast prototype, cannot help because its ground-based astronomy budget has been stretched to the limit by the projected cost of joining the European Southern Observatory.
Negotiations to join ESO have overcome a number of obstacles and a treaty could be signed by July 2002. However, the project's multimillion-pound entry fee has left little money for new projects.
A bid for backing from the Joint Infrastructure Fund was rejected last year.
John Baldwin, emeritus professor of radio astronomy at Cambridge, said: "At the moment it seems out of the question that PPARC would provide the money. I would be sorry to see things grind to a halt."
His team, headed by Chris Haniff, was the first to demonstrate the technology of Coast in 1996. The device, based in a field outside Cambridge, is an optical interferometer that combines signals from four widely separated 40cm mirrors, currently 50m apart. This gives the telescope far greater resolving power than conventional instruments.
Coast astronomers were among the first to see the surface of a distant star and have recently directly observed hot gas disks and what could be a binary star stripping the atmosphere away from its partner.
Their lead is being followed by teams from France, Australia and the United States, who are developing the technology.
Coast's successor was to have 15 large mirrors separated by up to 500m and would have been built in a location better suited to astronomy, such as Tenerife. Dr Haniff said it would have been able to reveal the active centres of galaxies where supermassive black holes are thought to lurk.