Paris

Officials at the European Commission have rebutted claims that an expert panel favours Spain as the potential host for ITER, the proposed international fusion experiment.

Two sites — one at Cadarache in France, the other at Vandellòs near Barcelona in Spain — are vying to be picked as Europe's candidate to host the US$5-billion project.

The commission set up the committee of seven industrialists and scientists in May to advise Europe's ministers, who this autumn will choose just one site as the European candidate to compete with Canada and Japan to host ITER.

Reports leaked earlier this month that the panel, chaired by David King, the UK government's science adviser, preferred Vandellòs (see Nature 424, 606; 2003) were confirmed at the time by separate sources. But they may have reflected wishful thinking, says a source close to the panel. In reality the committee is “deeply divided”, he says, and its report, scheduled for mid-summer, is unlikely to be ready until early next month.

The committee has “not been given the remit to produce a verdict”, a commission official says — only to provide an impartial assessment of both sites on the basis of such criteria as scientific and industrial expertise and site-specific costs.

The final choice of site will come not from the committee or from the commission, but from the European Council of Ministers, which is scheduled to meet at the end of September, says the committee source.

The choice of site is politically delicate, the official notes. The partners working on the research reactor — the European Union, Canada, Japan, Russia, China and the United States — hope to select a site by the end of the year. The United States has signalled its opposition to France as the site for ITER (see Nature 423, 211; 200310.1038/423211a).