Some people do not agree with Chris Grayling’s plans for judicial review. Others do – though I have yet to meet many in the legal profession, and what supporters there are tend to be limited to 300-odd MPs in the House of Commons.

Last week they shuffled through the voting chamber to reject Lords amendments to the Criminal Justice and Courts Bill covering judicial review.

It now turns out that MPs were misled by the lord chancellor before they took their vote. Whatever stance you take on the reforms themselves, the gravity of this mistake cannot be overstated.

Chris Grayling has written to one of the two Conservative MPs who rebelled on the vote to explain that he made a mistake during the debate. Grayling had said that a key clause to restrict granting permission for JR was offset by the bill allowing leeway to judges in ‘exceptional circumstances’.

In the letter, Grayling admitted no such exceptional circumstances provision exists in this clause. This goes beyond a simple oversight. It was a crucial error which was used to win favour for a controversial bill. The vote was won on false pretences.

The response from peers in the House of Lords was indignant bordering on furious.

Conservative peer Lord Deben (John Gummer) said Grayling's mistake was ‘damaging’. He echoed the view of many colleagues when he said the matter had to return to the Commons as MPs had been misled. ‘We have to give the other house an opportunity to reverse the decision that it made when it was not in full possession of the facts,’ said Deben.

Curiously, peers kept saying the lord chancellor had apologised – but on the basis of his letter, there was nothing of the sort.

Chris Grayling has had a pretty wretched year, losing three judicial reviews and facing protests from lawyers over his ongoing cuts programme.

But this is the lowest point by far. It would appear that Grayling does not understand his own bill.

Either way, there was no choice but to send it back to the Commons. Let’s hope that more than a handful of MPs turn up for the next debate - barely 20 turned up to actually hear Grayling’s error - as we will need to scrutinise every word next time.

John Hyde is Gazette deputy news editor