Liz Truss has used her first address at the Conservative party conference as lord chancellor to attack the lack of diversity of the legal profession, singling out the Supreme Court as an example.

The justice secretary told the conference that a modern justice system was not just reflected in practices and processes ‘but in its people’.

She said: ‘Currently only one in seven of QCs and one in three of partners in law firms are women. Fewer than one in 10 judges come from ethnic minorities. Only a quarter went to state school.

‘This is modern Britain – we can do better than this.’

Singling out the Supreme Court, Truss (pictured) asked: ‘Can it be right that out of 12 judges in the Supreme Court only one is a woman and not a single one is from an ethnic minority?

‘This would be difficult to justify in any boardroom or around the cabinet table.’

Pledging to open up the justice system, Truss told the conference she would be working to ‘break down barriers’ to ensure people from all backgrounds ‘can rise through the profession and that merit wins out’.

Pledging a justice system based on human rights, Truss said the Ministry of Justice’s proposals on a British bill of rights ‘will be the next step forward’.

Although the ministry recently unveiled a £1bn initiative to modernise the justice system, Truss used most of her speech to discuss prison reform.

Initiatives announced today include giving prison staff more time to directly supervise offenders.

The ministry will invest £14m to provide more than 400 additional staff in prisons that have experienced sharp rises in violence in recent years.

Truss also announced a new MoJ campaign to increase the number of former armed forces personnel becoming prison officers.