Staff at 65 courts in England and Wales will walk out for nine days in a bitter dispute over an "unworkable" new system which left workers having to work longer hours.
Trade union PCS today announced that strikes by legal advisors and court associates will go ahead on October 22 to 30 - adding to chaos across the legal system.
The action is separate to industrial action announced earlier this year by barristers as pressure mounts on the government to reach a deal with workers.
Workers complain they are forced to work longer hours - often until midnight - to record case results on the controversial Common Platform system.
PCS members had been due to strike last month, but postponed the action following the death of the Queen.
The system had been paused by Her Majesty’s Courts and Tribunal Service (HMCTS) for negotiations, but PCS confirmed today that these have failed.
Union general secretary Mark Serwotka said: “We’ve been left with no choice but to call strike action. Managers are ignoring the evidence in front of them – that Common Platform is simply unworkable.
“It’s adversely affecting our members’ health and their ability to do their jobs and is detrimental to the delivery of justice.
"HMCTS managers should listen to our members and stop the roll out immediately.”
Despite HMCTS saying trials were a success, a staff survey found tasks took longer, levels of stress increased, and work-life balance was negatively impacted.
Some have been forced to work until midnight to keep up, PCS said in a statement.
The courts affected are:
Aberystwyth Justice Centre
Aldershot Justice Centre
Barrow-In-Furness Magistrates' Court
Basingstoke Magistrates’ Court
Brighton Magistrates' Court
Bristol Magistrates' Court and Tribunals Hearing Centre
Caernarfon Justice Centre
Cambridge Magistrates’ Court
Cardiff Magistrates’ Court
Carlisle Magistrates' Court
Crawley Magistrates’ Court
Crewe (South Cheshire) Magistrates' Court
Derby Magistrates' Court
Durham County Court and Family Court
Ealing Magistrates’ Court
Gateshead Law Courts
Grimsby Magistrates' Court and Family Court
Guildford Magistrates' Court and Family Court
Hastings Magistrates' Court
Haverfordwest Magistrates' Court
Hereford Justice Centre
High Wycombe Magistrates' Court and Family Court
Kidderminster Magistrates' Court
Lavender Hill Magistrates’ Court
Lincoln Magistrates' Court
Liverpool and Knowsley Magistrates’ Court
Liverpool Civil and Family Court
Llanelli Magistrates' Court
Luton and South Bedfordshire Magistrates' Court
Manchester Magistrates’ Court
Mansfield Magistrates’ and County Court
Mid and South East Northumberland Law Courts
Milton Keynes Magistrates’ Court and Family Court
Mold Justice Centre
Newcastle Upon Tyne Crown Court and Magistrates' Court
Newport (South Wales) Magistrates’ Court
Newton Aycliffe Magistrates' Court
North Somerset Magistrates' Court
North Staffordshire Justice Centre
North Tyneside Magistrates' Court
Nottingham Magistrates Court
Oxford Magistrates' Court
Peterborough Magistrates' Court
Portsmouth Magistrates' Court
Reading Magistrates' Court and Family Court
Sefton Magistrates’ Court
South Tyneside Magistrates’ Court
St Albans Magistrates' Court
Staines Magistrates’ Court and Family Court
Stockport Magistrates’ Court
Sunderland County, Family, Magistrates' and Tribunals Hearings
Swindon Magistrates' Court
Tameside Magistrates’ Court
Teesside Magistrates' Court
Telford Magistrates' Court
Uxbridge Magistrates’ Court
Warrington Magistrates’ Court
West Hampshire Magistrates' Court
Wigan and Leigh Magistrates’ Court
Willesden Magistrates’ Court
Wimbledon Magistrates' Court
Worcester Justice Centre
Worthing Magistrates’ Court
Yeovil County, Family and Magistrates’ Court