Williams has used its veto power to block Michael Schumacher's test in the 2009 Ferrari, the Italian sports newspaper La Gazzetta dello Sport claims.
In view of Felipe Massa's accident and the return of Schumacher as his substitute, Ferrari asked the FIA and its nine team rivals if a one-off exemption to the in-season test ban might be granted.
FOTA vice-chairman and Toyota president John Howett reacted by saying he believed all eight FOTA members had agreed, but the answer of the other stakeholders was not known.
Italy's La Gazzetta however reports that while Force India is still contemplating the matter, Williams issued a categorical 'no'. Full unanimity is required for such requests.
The German newspaper Bild Zeitung said Schumacher, 40, still wants to test some time this week, but may have to do it now at the wheel of a privately-owned F2007.
Schumacher did nearly 70 laps in the two-year old car at Mugello last Friday.
More time in Fiat's Turin simulator is also off the agenda for Schumacher: a Ferrari spokesman said operating the machinery would be contrary to the F1 factory closures.
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