A NSW Supreme Court judge has called for "urgent" action to resolve the legal aid funding crisis after a high-profile murder trial slated to start in Sydney on Monday was delayed until 2020 because defence barristers refused to accept low legal aid rates.

Three men were due to stand trial on Monday over the alleged murders in 2016 of underworld figure Pasquale Barbaro, who was gunned down outside a house in Earlwood in Sydney's south, and Mehmet Yilmaz, who was shot as he left the home of a Comanchero bikie.

Pasquale Timothy Barbaro.

Supreme Court Justice Desmond Fagan vacated the trial date last week after the court heard the trio had failed to secure defence counsel for the four-month trial because barristers with the necessary skills were "reluctant to make themselves available for a long trial at Legal Aid fee scales".

Justice Fagan said the "inability to secure the services of trial counsel at Legal Aid rates on reasonable notice for a long trial is a problem that requires urgent attention to enable this court to do its work".