Madrid - A major ETA attack in Madrid was prevented by a routine traffic check near Calatayud in north-eastern Spain, the Interior Ministry said yesterday, Jane Walker writes from Madrid. A van, whose driver had committed a minor traffic infringement, was stopped by a highway patrol and was found to contain almost one tonne of explosives. It was primed and had it exploded it would have been one of the largest bombs ever used by ETA. The driver of the vehicle was detained. He was later named as Mr Jose Maria Novoa, who stood as a candidate in the last municipal elections for Euskal Herritarrok, the party closely linked to ETA. It is now almost three weeks since ETA announced the ending of its 14-month ceasefire and security forces have been warning of imminent attacks. This week it was revealed that ETA had begun a new campaign to raise funds when 30 Basque businessmen received letters demanding the payment of protection money or "revolutionary taxes".