The UK synchrotron, once known as Diamond, is intended to replace the ageing second-generation SRS machine at the Daresbury Laboratory in Cheshire, although the location of the new machine has still to be decided. The Wellcome Trust is contributing £110m to the construction costs. Biologists are likely to be the main users of the machine, followed by physicists and chemists.

French scientists had been lobbying to build Soleil for over a decade. However Claude Allègre, the science minister, has been opposed to the project ever since he was appointed in 1997. This week he announced that the UK, German, Italian and French governments have agreed to form a European group to plan future synchrotron and neutron sources for the continent, and make proposals for European investment in these areas.