The judges on Australia's High Court decided exactly half of the cases heard in 2010 unanimously - easily the highest rate of agreement seen in more than 30 years - according to a report presented today at the tenth annual Constitutional Law Conference.

The study of the High Court's decisions in 2010 by Dr Andrew Lynch and Professor George Williams, from the University of New South Wales Gilbert + Tobin Centre of Public Law, shows that in 50 percent of all cases decided last year, the Court was able to reach a single opinion as to the outcome.

"The swing towards a high rate of unanimity was a clear feature of the decisions of 2009," Dr Lynch said. "But frankly, our expectation was that on a court of seven judges, disagreement would soon reassert itself. Yet in 2010 the Court's members actually increased the frequency with which they agreed with each other."

This was also reflected in the delivery of no fewer than three unanimous opinions in constitutional law cases, which traditionally confound agreement.

"It was particularly striking that the Court chose to speak as one in the important decision upholding the rights of offshore asylum seekers to procedural fairness," Lynch and Williams said.

The authors said some of the Court's success in reaching consensus must presumably be attributed to the leadership and management style of the new Chief Justice. The Hon Robert French was appointed by the Rudd government to the position of Chief Justice from the Federal Court at the end of 2008.

The study also found that in 2010 no fewer than three new judicial partnerships appeared to emerge on the Court. While previously Justices William Gummow and Kenneth Hayne were the dominant team of co-authors, last year Justice Gummow wrote most often with Chief Justice French while Justices Hayne and Susan Kiefel were most frequently paired. The third discernible partnership was between Justices Susan Crennan and Virginia Bell, the Court's most recent appointee.

For the second year running, the member of the Court most often in dissent was Justice Dyson Heydon. Heydon wrote far less often with his colleagues than they did with each other and he disagreed with the result in about 15 percent of cases on which he sat.

Media contact: Steve Offner, UNSW Media Office, (02) 9385 8107, 0424 580 208, s.offner@unsw.edu.au