The analysis of starting salaries offered to newly qualified lawyers found that the pay gap between corporate and criminal law has jumped to as much as £150,000 in London, when bonuses are taken into account.

The study revealed that even some of the most highly-regarded criminal law firms in London, which represent individuals in criminal cases, pay their newly-qualified solicitors an annual salary of between £35,000 and £50,000.

By contrast, newly-qualified lawyers acting for businesses can now earn vast sums after a prolonged battle for talent sent pay offers soaring. Starting salaries typically range from around £70,000 at a mid-sized City law firm to £120,000 at a Magic Circle firm. The top-tier US law firms with offices in London pay most of all - with starting salaries of up to £180,000, alongside £20,000 bonuses, not uncommon.

The rapidly widening pay gap comes as the Criminal Bar Association, which represents criminal barristers in England and Wales, presses ahead with an indefinite strike to demand a 25 per cent increase in legal aid fees. A survey of its members found 25 per cent intend to leave the profession, and it reports that the number of junior criminal barristers has plunged 38 per cent in just a year.

Meanwhile the Law Society reports a fall in both the number of firms and the number of solicitors providing legal advice to people brought in for questioning at police stations, with many criminal lawyers “voting with their feet.”

Akshay Nayak, managing director at Tenhaven, said: “The pay gap has turned into a gulf. While there has long been a mismatch between what criminal and corporate lawyers are paid, rocketing salaries at many commercial law firms mean that for a newly-qualified lawyer the difference can be as much as £150,000 when bonuses are included.

“While successful commercial law firms are fighting a cheque book battle for the best talent, criminal firms tend to be smaller and far less profitable - meaning they typically pay much less.

“The criminal justice system and the right to a fair trial depend on the legal profession, so the inevitable ‘brain drain’ of criminal lawyers, or, indeed, the decision by best-in-class graduates not to enter the criminal law at all, is worrying.

“It’s complicated by the fact that criminal lawyers cannot easily transition into commercial law, and corporate law firms generally will not advise on criminal matters. Those voting with their feet may be leaving the law entirely, and criminal law firms will find it increasingly hard to recruit top talent from the current cohort of legal students when their commercial counterparts offer such jaw-dropping salaries to graduates.”