Trial by jury in England and Wales is under threat as never before. Not for all prosecutions, of course: even if the government goes ahead with the measures it is now considering, juries would still determine guilt or innocence in the most serious cases. And not for ever, if you believe the Justice Secretary: Robert Buckland insisted this week that the necessary legislation would be “sunsetted in an absolute way” — which I think means strictly time-limited.

I don’t doubt Buckland’s good faith. But the statute book is full of temporary measures that have been extended by subsequent ministers and then become permanent. Members of parliament cannot bind their successors.

The government’s thinking was first outlined by the Lord Chief Justice, Lord Burnett of Maldon, in an interview he gave me for the Radio 4 programme Law in Action. This, in itself, was curious. Burnett has regular meetings with Buckland and it is entirely appropriate that the Lord Chief Justice and the Lord Chancellor should discuss ways of coping with the growing backlog of jury trials, caused partly by the coronavirus pandemic. But it is normal practice for ministers to announce their proposals before judges offer their views.

During the interview, broadcast last week, Burnett stressed repeatedly that policy was a matter for Buckland and, ultimately, parliament. He expected no change to the way that serious charges — such as rape and murder — were tried. The least serious offences would continue to be decided by magistrates.

But between those extremes were cases — such as assault, theft and burglary — that could be tried either by magistrates or by a judge and jury. At present, a defendant charged with one of these so-called “either-way” offences can insist on jury trial.

“A possibility that I believe is worthy of consideration by policymakers,” Burnett told me, “is to legislate to enable, for a short time, the disposal of either-way trials in the Crown Court by a judge sitting with two magistrates. That would retain the lay public involvement in trials, but give rise to none of the difficulties of social distancing that attach to having a jury involved in a trial.”

Reducing jury trials would reduce the backlog more quickly than any other option. But at what cost?

A week later, the Justice Secretary referred to Burnett’s proposal in oral evidence to the Commons justice committee. “There may well be a way forward here in managing those cases with a judge and two magistrates,” he told MPs. 

“That’s a shift in position for the government,” observed Sir Bob Neill, the committee chairman. Buckland explained that ministers remained opposed to either-way cases being tried by a judge sitting alone. Switching to a judge and two magistrates was a “last resort” but it would improve court capacity by up to 40% — which is much more than Buckland’s other option of reducing the number of jurors to support social distancing in court. It could also be limited to offences with a maximum penalty of two years’ imprisonment, so defendants facing the more serious assault charges could still insist on jury trial.

Withdrawing the right to jury trial would require legislation. Buckland said this would need to be passed by parliament within the next four weeks so that it could take effect in September. The reform could eliminate the backlog by Easter.

That backlog would have been smaller if successive ministers had not deliberately reduced judges’ sitting days to save money. Buckland said he had increased the number of hearings and would be hiring temporary accommodation to increase capacity.  Lawyers said he should do very much more.

There is no doubt that reducing the availability of jury trials would reduce the backlog more quickly than any other option. But at what cost? This would be a major constitutional change which the government is proposing to rush through with little thought and no consultation.

What, for example, would the magistrates’ role be? When they now sit with a judge in the Crown Court to hear appeals from the magistrates’ court, magistrates can out-vote the judge in deciding the appeal — but they must accept the judge’s decision on any question of law.

Under the government’s plans, it would presumably be for the judge and magistrates, sitting together, to decide on the defendant’s guilt or innocence. Would they have to be unanimous? Or could the magistrates convict even if the judge thought the case had not been proved? 

A judge can currently direct a jury to acquit. Would the judge retain that power? What if the judge thought the case had been proved and the magistrates were unsure? Would they ever dare to out-vote a judge? And would they have any role in sentencing?

The judge’s role would change completely. Until now, it has been the jury’s job to decide guilt or innocence. Would the judge have to give a detailed summary of the evidence in the event of a conviction? And would the magistrates be expected to contribute to it, even though most of them are not lawyers? Wouldn’t that increase the length of the hearing?

Faced with this level of uncertainty, many defendants will simply take their chances and agree to be tried in the magistrates’ court. That, presumably, is what the government is hoping. Since these defendants will be facing relatively serious charges, many are likely to be tried by full-time district judges — sitting alone. And yet trial by judge alone in either-way cases is something that both Burnett and Buckland say they are firmly against.

Personally, I have my doubts about the jury system. The vast majority of criminal cases in England and Wales are tried without them. There is something to be said for giving defendants accused of offences such as fraud the right to choose trial by judge alone.

But past governments have found to their cost that even the most benign tinkering with trial by jury leads to an outpouring of public support for what’s seen as the ultimate defence against tyranny. References to Magna Carta may owe more to emotion than to history — but they remain deeply felt.

Most of the backlog in jury trials predates the pandemic and is the fault of ministers. It is now the government’s responsibility to make up the shortfall by paying for more sitting hours, more temporary courtrooms and more lawyers. Once the courts are running smoothly again, we can talk about reforming the system. But rushed legislation usually makes things worse.