Crown court trials across England and Wales were suspended or collapsed on Monday as judges attempted to find safer ways for juries and lawyers to conduct hearings.

There have been suggestions, including from the Ministry of Justice, that courts move to handling urgent work only during the coronavirus crisis, but no one has defined what types of cases that might involve.

A statement issued by the lord chief justice, Lord Burnett of Maldon, said hearings were being paused while measures that respected the need for physical distancing were considered to prevent infection spreading.

Burnett’s decision followed complaints about the safety of continuing with physical court hearings while much of the rest of the the country shuts down.

The head of the judiciary said: “A review of the arrangements in our courts is called for. I have decided that we need to pause jury trials for a short time to enable appropriate precautions to be put in place.

“My unequivocal position is that no jury trials or other physical hearings can take place unless it is safe for them to do so.” Judges should conduct cases using remote technology such as telephone and video links where possible he said.

His early morning announcement stopped many hearings from resuming or starting. The pattern across the country was not uniform, however, because decisions about whether individual cases should go ahead has been placed in the hands of local judges.

The jury at the Old Bailey trial of three teenagers accused of the murder of PC Andrew Harper was discharged after a third juror went into isolation over the weekend.

In a sign that hearings are unlikely to resume in any number for a long time, Caroline Goodwin QC, the chair of the Criminal Bar Association (CBA), said: “The political pressure to keep courts open is unacceptable, not least given their previous neglect and the lack of concern for any of the endemic delays or issues in the criminal justice system.

“Within the recent past there was no care for the removal of cases from the criminal lists. Now there is an unacceptable pressure to press on regardless. That in simple terms is wrong, is dangerous and fails to exercise any duty of care to court users. When, and only when, it is safe, can hearings be resumed.”

Lawyers for the WikiLeaks founder, Julian Assange, have signalled that they will make a bail application for him on Wednesday at Westminster magistrates court on the grounds that he is vulnerable to the Covid-19 outbreak in Belmarsh prison where he is on remand. His extradition appeal is part-heard.

The chair of the Bar Council in England and Wales, Amanda Pinto QC, issued fresh guidance for barristers urging them to stay away from court unless instructed otherwise. “For those who are unclear whether they should go to court today or in the immediate future the default position is to stay away unless yours is one of those rare hearings which must be in person and the court tells you to go in,” she said.

“Listing officers in every crown court are now working through their lists for today and the next few days to identify the hearings that will and will not happen in person.”

Elsewhere defendants and lawyers were still expected at court. The CBA retweeted a comment from one barrister saying: “Business as usual at Stratford youth court. No guidance on what ‘urgent’ means. No directive to adjourn bail cases. Parents and young people and advocates waiting outside court room. Not safe for anyone here.”

Another barrister, Oliver Kirk, tweeted: “Report from the coal face: People literally risking their lives and those of us all to come to court for offences over a year old to be given a trial date next year.”

The FDA union, which represents CPS prosecutors, called for more detailed guidance. “We have been calling on the MoJ to suspend all but the most urgent cases in order to protect the health and safety of everyone who works in or uses the courts, so this [announcement by Burnett] is a welcome development,” the FDA’s national officer, Steven Littlewood, said.

“We are also pleased to note the commitment to appropriate health and safety measure in courts. Our members have repeatedly raised concerns about a lack of proper social distancing as well as insanitary conditions at courts, including a lack of soap and hand sanitiser.

“But for these problems to be rectified and to ensure the health and safety of those at court a full risk assessment carried out before anyone is expected to attend. We are calling for this to take place and for the guidance to require this.”