Barristers are planning to take industrial action over cuts to the "collapsing" criminal justice system.
Court proceedings across the country face disruption as some lawyers will refuse to take on new cases and stage walkouts.
Leading legal chambers Doughty Street, Garden Row and 25 Bedford Row are among those set to take part in the action.
Angela Rafferty QC, Chair:
Ministers are making an unequivocal commitment to underfund the legal system
We will fight to improve the #CJS for us and everyone else
90% surveyed wanted to act to secure proper investment
We announce this action with heavy hearts#Action4Justice
-- The CBA (@TheCriminalBar) March 29, 2018
The Criminal Bar Association (CBA) has warned that prisons, courts, the police and probation services are "underfunded and in chaos".
Chair Angela Rafferty QC said "relentless cuts" have resulted in "near collapse" of the justice system.
"You cannot have a national asset and treat it like this," she added.
She said under-funding means cases are not being properly investigated by the police and CPS, there is uncertainty and delay at court and "unnecessary distress" for witnesses, victims and defendants.
"Meanwhile the poor and vulnerable in society are being denied access to justice," she added.
"The system is desperate, it cannot endure any more cuts."
The recent disclosure crisis, which led to the collapse of a number of rape trials last year, has also highlighted "the appalling state of our system", a CBA spokesman said.
"Criminal barristers are the ones who have to pick up the pieces and are not being paid for the disclosure work which stops people going to prison," he said.
The CBA has advised its 4,000 members to take action after 90% voted in favour, with a turnout of around 55%.
More than a third of criminal barristers said they are considering leaving the profession, with the main reason being low income and work-life balance, according to a survey by the General Council of the Bar.
-- The Bar Council (@thebarcouncil) March 29, 2018
A spokesman for the Bar Council said: "The Ministry of Justice budget has been slashed across the board in the last decade.
"The effects, in every area, are becoming ever clearer: courts and prisons in a deplorable state of repair, leading to unacceptable conditions, litigants struggling to deal with their own cases without legal help in the most trying of circumstances, overloaded courts and judges, increasing delays and judicial morale at rock bottom, to name but a few.
"While the current investment in the court reform programme is substantial, it cannot hope to reverse all of the harm that has already been done, and continues to be done, and its focus is really elsewhere."
A Ministry of Justice spokeswoman said: "We are extremely disappointed with the position the Criminal Bar Association has taken today, especially given that they and other members of the bar participated fully in the design of the scheme.
"Our reforms will reflect the actual work done in court, representing better value for the taxpayer, and will replace an archaic scheme under which barristers were able to bill by pages of evidence.
"We greatly value the work of criminal advocates and will continue to engage with the bar moving forwards."