Officials at the House of Lords later reduced the claim made by Michael Mansfield QC - which worked out to �416 an hour - to just half the original figure.

Mr Mansfield went on to claim a further �1,000 a day for the subsequent two days of the hearing. House of Lords officials allowed this to stand.

The sum was one of four which prompted the current unprecedented inquiry into legal aid bills for cases heard before the Lords.

Michael Mansfield QC's claims came under the spotlight

On Wednesday, the inquiry was told top criminal barristers should earn no more than �200,000 a year from legal aid, the equivalent to senior hospital consultants.

Barristers ridiculed the idea as "over the line of absurdity".

Mr Mansfield ran up his �20,000 bill for his work in an appeal against a murder conviction, which included 43 hours preparation and the first day in court.

Mr Nigel Pleming QC, for the Lord Chancellor, told the hearing that the average day before the Law Lords lasted five hours - giving a total worked by Mr Mansfield of 48 hours.

"Excessive billing"

Mr Pleming cited another example of "excessive billing" in top QC, Richard Henriques. He claimed �288 an hour brief fee for another murder case appeal heard by the Law Lords.

He worked 80.5 hours to prepare, at a self-assessed rate of �175 an hour. He then added a 65% "uplift" in order "to reflect the care, control and conduct of a case in the House of Lords".

He then added in expenses and rounded the total up to �25,000.

That claim has not yet been settled.

Fees rose 400%

Mr Pleming told the hearing that in another case the brief fees - which traditionally cover preparation of the case and the first day in court - for defence counsel had risen by more than 400% as the case went up through the appeal system.

Another senior barrister, Peter Feinberg QC, and his junior Benjamin Squirrell, claimed brief fees of �15,000 between them at a six-day Old Bailey trial in 1994. They were allowed �10,500.

When the case went to appeal, they claimed �7,500 and were allowed �4,000.

By the time it reached the House of Lords, their brief fees of �69,311 were more than four times those of the original trial.