“Whilst we will be examining the detail of the Government’s proposals before responding more fully, it is quite clear that the criminal justice system will be the worse for these changes,” he said.

In the final package of pay cuts to Crown Court legal aid advocacy – revealed on 27 February in the Ministry’s response to Transforming legal aid: next steps – a “simplified” version of the advocates graduated fee scheme (AGFS), based on that used by the Crown Prosecution Service, is to be implemented this summer.

Barristers’ fees will be cut “on average” by 6%; with junior barristers earning less than £50,000 a year seeing reductions of 2%. Solicitors’ fees are to be reduced by 17.5% in two stages and the number of firms eligible for duty solicitor contracts limited to 525.

In a letter to the Bar confirming the cuts, Lord Chancellor Chris Grayling wrote: “I have genuine respect for the traditions of the independent Bar, and the high quality advocacy that you provide. It was for this reason that I did not opt for more radical structural change to advocacy services.”

Measures have been put forward “to ease the eff ect on the Bar” and “support the profession”, including restoring cracked-trial fees for elected either-way cases where the prosecution offers no evidence on all counts, and introducing interim payments for trials due to last 10 days or more.

Sir Brian Leveson, President of the Queen’s Bench Division, will lead a review to identify ways to streamline criminal proceedings, such as reducing the number of pre-trial hearings, so that barristers can “take on more cases and earn more fees within the same amount of time”.

There will be a full review of the new scheme next summer which, he pledged, would not be an opportunity for more cuts.

“[U]nder this Government, there will be no further reduction to advocacy fees, and in my view there are clear limits to how far fees can be cut,” the Lord Chancellor stated.

But the Bar Chairman said that delaying the review for one year was “putting the cart before the horse”.

“A review now would have shown, as we have consistently said, that there is no financial case for another round of cuts, after three years of cuts, cuts and more cuts.

“The Ministry of Justice’s own statistics show that cost of the criminal justice system has fallen in recent years at a faster rate than the rest of the Department’s expenditure.

Moreover, Crown Court advocates have already borne a disproportionate share of the reductions in spending,” Lavender said.

The Bar Council pointed out that fee rates paid to Crown Court advocates had fallen by 21% on average since 2007, a 37% fall in real terms after allowing for inflation. Spending on the AGFS had fallen from £275m in 2010/11 to £242m in 2012/13, and a further 10% fall was expected as the impacts of earlier cuts make themselves felt.

Lavender said: “Our worst fears have been confirmed. Across England and Wales, criminal barristers, who work hard in the public interest, will be dismayed and demoralised. Regrettably, many skilled and experienced advocates are likely to have to leave criminal practice altogether. The quality of justice will suffer as a result, and the harm done may well be irreparable.”

Meanwhile, the Attorney General is to appoint an amicus curiae in R v Crawley to assist the court with matters arising. Due to start in April, the case is one of those affected by a Bar boycott of very high cost cases following last year’s 30% cut to VHCC fees.