The trailblazing barrister, Sir Louis Blom-Cooper QC, who championed prison reform and campaigned against the death sentence, has died aged 92.

The son of a fruit and vegetables trader, he was born in London, studied law at King’s College London, Fitzwilliam College, Cambridge, and the Municipal University of Amsterdam, where he obtained a doctorate in 1954.

He was called to the Bar by Middle Temple in 1952, took Silk in 1970 and was knighted in 1992. During the 1970s and 80s he was head of Goldsmiths Chambers before moving to Doughty Street Chambers on its foundation.

Among his notable cases, in 1983 he represented Stephen Raymond in the landmark House of Lords case of Raymond v Honey, which established the right of convicted prisoners to have access to the courts and sue the prison authorities without first seeking the authorities’ permission.

While his efforts in 1976 to save the life of revolutionary Michael de Freitas, arguing that the imposition of the death penalty after long delay in Trinidad was unconstitutional, were unsuccessful, they laid the foundation for Geoffrey Robertson’s successful argument in the case of Pratt v Morgan in 1994.

Geoffrey Robertson QC, joint head of Doughty Street Chambers, described him as ‘one of the most intellectually brilliantcounselin the last half-century’.

He said: ‘He will be remembered by leaders of today’s Bar as one who inspired them to work in human rights at a time, in the 70s and 80s, when this was looked down on by a reactionary profession.’

In his obituary in The Guardian, Edward Fitzgerald QC, the other joint head of Doughty Street Chambers, praised him as a ‘fearless legal trailblazer and pioneer’ and a ‘courageous advocate’.

‘Popular and gregarious, Louis was as likely to have a meal with an ex-prisoner as a law lord,’ he wrote.