The Prime Minister is to "get a grip" on people forcing unnecessary delays to Government policy by cracking down on the "massive growth industry" of Judicial Review. David Cameron told business leaders today:

"When this country was at war in the 40s, Whitehall underwent a revolution. … everything was thrown at 'the overriding purpose' of beating Hitler. … this country is in the economic equivalent of war today – and we need the same spirit. We need to forget about crossing every 't' and dotting every 'i' – and we need to throw everything we've got at winning in this global race."

The detail of the changes is yet to be revealed (update – more detail is now available on the Ministry of Justice website, including the promise of a public consultation), but the PM plans to "reduce the time limit when people can bring cases; charge more for reviews – so people think twice about time-wasting."

Clearly some of the PM's Dunkirk spirit rhetoric is aimed at cheering up business leaders, who need a lot of that at the moment. But putting the rhetoric aside, there is cause for concern here.

First, the underlying assumption is that Judicial Review, the right to challenge decisions of public authorities in court within three months of them being made, has grown out of control since the 1970s.

Has any proper analysis been done? There are reasons for the growth in Judicial Review which are unconnected to the rapaciousness of lawyers and unnecessary bureaucracy , such as the growth of the state, the decrease in trust of politicians and the more general point that Judicial Review is actually quite a good way of guaranteeing that decisions of public authorities are reasonable and fair.

Anyone who works in administrative law, as the practice of Judicial Review is known, has seen really poor decisions, which had been upheld by internal public authority appeals processes (such as they exist), eviscerated by judges. The mere threat of judicial oversight can lead to irrational decisions being made again – for example, in the recent fuss over the West coast rail franchise.

Secondly, there are a some worrying statements which are said to underly the changes. For example, the original BBC story (screen grab here) said Downing Street figures showed "Around one in six [judicial review] applications was granted". Following a little fact checking on Twitter, that has now been removed. Whilst it is right that permission to proceed (the first stage) is granted in around 6.5% of Judicial Review applications, only around 1% actually succeed at the substantive stage, that is win overall – see page 65 of the statistics for 2011. Which statistics are being used to justify this decision in Whitehall?

Of course, Government and business leaders have every right to worry if the courts are being slow, inefficient or over-bureaucratic in holding up the decisions of public authorities. The three-month time limit to bring a Judicial Review is much shorter than in most other litigation settings. This is in recognition of the fact that public authorities need to be able to get on with making decisions and not be unduly delayed by unmeritorious court claims.

But it seems that the real problem here is court delays, not the judicial review system itself. At least, that is the thrust of the Prime Minister's comments. From my experience, it sometimes takes around a year for a full judicial review to be heard, which makes a mockery of the initial three-month time limit – although judicial reviews of more urgent decisions tend to take a matter of weeks. Of course one of the best ways to tackle court delays would be to increase funding to the justice system. But that is unlikely to happen given the very significant cuts to the Ministry of Justice's budget.

Unless the system can be made more efficient – for example, by further cutting the number of claims which are dealt with by High Court Judges – the only other option is to limit the rights of individuals to challenge Government decisions. And there may be problems there for the rule of law.

Thirdly, will the entire Judicial Review system be affected or just the part of it which concerns the kinds of decisions which affect business? The vast majority of Judicial Review applications are about immigration, not planning, so this is a very important question indeed. Whilst increasing the speed of planning challenges could (at a stretch – see below) be justified by the 'wartime' analogy, that logic is becomes more strained when it comes to immigration decisions.

Finally, it may be rhetoric, but this is the second time in a week that the Prime Minister has expressed frustration at having to cross his 't's' and 'i's'. He said in relation to Abu Qatada, who has avoided deportation to Jordan:

"We have moved heaven and earth to try and comply with every single dot and comma of every single convention to get him out of this country."

Lawyers will be very concerned indeed about this. The wartime analogy is also somewhat depressing. During wartime, the state becomes more authoritarian as it is focussed on a single existential threat. Niceties of rights protection and civil liberties tend to be suspended. Nobody could seriously want this to apply because we are facing the real but certainly not existential threat of a recession.

Since the Prime Minister is invoking the Second World War, it seems appropriate to invoke perhaps the most famous dissenting judgment in our legal history, that of Lord Atkin in Liversidge v Anderson [1941] UKHL 1. He said:

"In this country amidst the clash of arms the laws are not silent. They may be changed, but they speak the same language in war as in peace. It has always been one of the pillars of freedom, one of the principles of liberty for which on recent authority we are now fighting, that the judges are no respecters of persons and stand between the subject and any attempted encroachments on his liberty by the executive, alert to see that any coercive action is justified in law."

Judges have become quite good at making sure, on behalf of individuals, that the Government dots its 'i's' and crosses its 't's'. To paraphrase Lord Atkin, we should think very carefully indeed before silencing the law.

Adam Wagner is a barrister and editor of UK Human Rights Blog, which is written by members of 1 Crown Office Row. Click here to follow Adam on Twitter.