Only four of Germany's 128 Eurofighter aircraft are operational and ready for combat in the event of a crisis, it was claimed yesterday.
The remaining aircraft have been grounded by technical problems and a shortage of combat missiles, according to Spiegel magazine.
The alleged problems would leave Germany unable to fulfil Nato commitments and could weaken the alliance's air capabilities.
The German Defence Ministry confirmed that some of its Eurofighters have are affected by technical issues but said details of how many aircraft remain operational are "classified".
Officially, the air force has 82 Eurofighters available to Nato reaction forces but Spiegel claims the majority are unable to fly combat missions and can only be used for training flights.