This dynamic eventually became the source of an acrimonious dispute between the two men.

NEWYORKER: The Rebellion Within

In an acrimonious dispute, which has run since the exam results were issued in August, head teachers repeatedly challenged Ofqual's credibility.

BBC: Court rejects bid to overturn GCSE grades

Details have also emerged of an acrimonious four-year dispute involving another senior radiologist and Great Ormond Street.

BBC: London

Even on the aircraft dispute, the shift to an independent arbiter may be more constructive than endless acrimonious bilateral negotiations.

ECONOMIST: Economic development