Governor Gavin Newsom, who was sworn in at the start of the year, will today sign an executive order granting a reprieve to prisoners on death row and closing down the execution chamber at San Quentin State Prison.

The state of California has not executed any prisoners since 2006, largely because of a series of protracted court battles over the executions process.

San Quentin State Prison swapped the gas chamber for executions by lethal injection in 1996, but the lethal injection process has been subject to several legal challenges - leading to a situation some commentators have called a de facto moratorium.

A proposal to abolish the death penalty in California previously went to a state-wide ballot in November 2016 and was rejected by 53 per cent of voters.

However, Governor Newsom, who ran for election on a platform of declaring a moratorium, is exercising his power to grant reprieves to take action unilaterally, CBS News reports.

In a statement, he said: “I do not believe that a civilised society can claim to be a leader in the world as long as its government continues to sanction the premeditated and discriminatory execution of its people.

“In short, the death penalty is inconsistent with our bedrock values and strikes at the very heart of what it means to be a Californian.”