Junior judges are being put on what are in effect zero-hours contracts as the criminal justice system succumbs to a fresh round of austerity and courtrooms are closed down, lawyers are warning.

Working days for recorders – part-time judges who are usually experienced barristers or solicitors – have been slashed and requests are being made for them to sit on the bench at impossibly short notice, according to the Criminal Bar Association.

The decline in sitting days for recorders is imposing additional strains on full-time, crown court judges. Some recorders have even received warning notices that if they do not fulfil their required annual quota of at least 15 days they may no longer be eligible to serve.

The Ministry of Justice denies that the reductions are due to financial problems and insists that because the number of cases going to court has fallen fewer recorders are required. The MoJ has suffered deeper cuts than any other Whitehall department since 2010.

The latest allocation of sitting days for recorders sent out by HM Courts and Tribunals Service (HMCTS) last week is, according to sources, the lowest since 2000-01 and the largest year-on-year percentage decrease since records began.

Caroline Goodwin QC, vice-chair of the Criminal Bar Association, said: “The present position appears to be that any sitting days offered to recorders are entirely ad hoc. The secretariat is notified only days before, if that – even the afternoon before if a court needs any recorders to sit. Exactly how recorders are to fulfil their sitting obligations and maintain any real career progression simply beggars belief. Lastminute.com appears to apply.

“If running court sitting timetables for recorders is reduced to a zero-hours culture then we are in a negative care culture for the public, symptomatic of a system starved of funds which cares little for court users – including complainants, witnesses and victims of crime.” Zero-hours contracts are widely used in part-time work organised for the employer’s convenience.

Earlier this month, Bob Neill MP, Conservative chair of the justice select committee, expressed concern in the Commons about “increasing reports of cases being adjourned, often at the last minute, for the lack of a judge being available, particularly in the crown and county courts. At the same time, courtrooms sit empty and HM Courts and Tribunals Service is not advertising vacancies for recorders – part-time judges who are willing and able to fill those vacancies.”

Derek Sweeting QC, chair of the Bar Council’s legal services committee, said: “The reduction in crown court cases ought to be leading to reduced waiting times and an improvement in efficiency but rather than taking the fall in cases as an opportunity to improve the system, the concern is that it’s being used as an opportunity to cut costs by reducing sitting days.

“Courtrooms with available judges should be dealing with cases that are ready for trial, not standing empty. There’s a lot of coxing and boxing with recorders being asked to sit urgently at short notice. It’s something of a zero-hours approach.”

In 2018 there was a 16% decrease in new crown court trials compared to the previous year. Last week, however, the Metropolitan police commissioner, Cressida Dick, expressed concern about “woefully low” rates for solving crimes, with courts “emptying” despite some offences rising.

An HMCTS spokesperson said: “Last year crown court trial waiting times were at their lowest since 2014, with this year’s allocation of sitting days reflecting this.

“Every effort is made to ensure recorders can fulfil their sitting days requirement and we would not penalise any recorder who does not do so through no fault of their own.”