The Criminal Bar Association has insisted today's action will not jeopardise trials, but warned that future trials could be at risk if the issue was not resolved.
It has been careful to call the walk out a "non-attendance" rather than a strike.
There will also be protests outside courts in London, Manchester, Liverpool, Leeds, Birmingham, Newcastle, Winchester, Bristol and Cardiff.
The Bar Standards Board has warned that any barristers who stay away from court will almost certainly be in breach of their professional code of conduct with "very serious consequences".
More top news
Donald Trump has wasted no time making his mark on international matters as well as domestic. So how will his presidency affect the world?
Another cold, frosty and foggy night for many. Northern and western areas will see thickening cloud, patchy rain and milder temperatures.
Temperatures have already plunged to -12C in some parts of the UK this winter - but Thursday could be the coldest day yet.