Today is David Lammy’s big day. The justice secretary has two opportunities to persuade MPs — and the public at large — to support his jury reforms. This morning, he and his ministers will answer questions in the chamber. And this afternoon he and his permanent secretary will give oral evidence to the Commons justice committee.

Restricting the availability of jury trial is not the only topic he will be asked about. But Lammy has allowed a huge head of steam to build up against his planned legislation. Barristers in general — and the Criminal Bar Association in particular — have condemned his proposals. Apart from victims’ representatives and the Magistrates’ Association, nobody has offered support for Lammy’s plans.

None of this should come as a surprise. Previous attempts to reduce the availability of jury trial have generally foundered. There may no good reason why defendants should be allowed to choose jury trial for offences that parliament has allowed to be tried by magistrates. But we are dealing here with emotions as much as logic and Lammy has failed to get through to a sceptical public.

A year has passed since Sir Brian Leveson was asked to consider “options for criminal court reform, with the aim of reducing demand on the crown court by retaining more cases in the lower courts”. The former judge was told that reforms could include:

• The reclassification of offences from triable-either-way to summary only.

• Consideration of magistrates’ sentencing powers.

• The introduction of an intermediate court.

• Any other structural changes to the courts or changes to mode of trial that will ensure the most proportionate use of resource.

So ministers have had plenty of time to lay the groundwork for these proposals. I was told that a bill was being prepared in the summer. Where is it? Far from seeing even a draft, there has not been a white paper — a policy document outlining the government’s plans. Pretty much all we have to go on is a written answer a couple of weeks ago — and even that leaves many questions unanswered. In an hour spent responding to MPs last week, the courts minister Sarah Sackman provided no more details of the government’s proposals.

That can only be because ministers are still unsure of their plans. On 2 December, Lammy told MPs:

The appeals process from magistrates’ courts will be reformed so that automatic appeals to the crown court in criminal cases are replaced with a permission stage, limited to points of law.

On 11 December, Sackman made it clear that appeals would not be limited to points of law after all:

Following reforms to the criminal courts, appellants will continue to have the right to appeal convictions and sentences received in both magistrates’ courts and the crown court. Permission to appeal will be granted by the judiciary where the appeal has a real prospect of success.

In contrast to the Sentencing Bill, which was launched while Shabana Mahmood was still justice secretary and has now almost completed its parliamentary passage, Lammy’s jury reforms seem remarkably fluid. How else are we to understand major differences between leaked proposals reported on 25 November and the announcement rushed out a week later?

Ministers are already telling us not to expect reforms to make a difference before the next election in three-and-a-half years’ time. But even that seems in doubt unless Lammy gets a grip in the next 12 hours.