EADS and Northrop Grumman, the duo that controversially pipped Boeing to a $35bn US Air Force refuelling tanker contract in February, have criticised the political backlash against the deal as antiquated and “extraordinarily unhealthy”.

Stepping up the rhetoric, Ralph Crosby, the US head of European defence group EADS, spoke out against politicians who had sought to interfere in the Pentagon’s value-driven procurement strategy.