One courtroom was originally set up at the Westminster HQ in Petty France, taking on cases from the east and west London family courts.
Now the ad-hoc court has been expanded with meeting spaces converted into a further three hearing rooms, as part of a renewed drive to boost court capacity especially in the family courts.
The first two new courtrooms at the MoJ are due to start hearing cases this week, with a further hearing room due to open next week.
The justice system was already struggling with case backlogs when it was plunged into crisis by the Covid-19 pandemic.
There are currently 16 “Nightingale” courts in operation around England and Wales, set up to boost capacity as the courts cope with coronavirus safety measures including social distancing.
The Lord Chief Justice, Lord Burnett of Maldon, revealed last week that the MoJ has been in talks with the Treasury and Downing Street over an extra £30 million in funding for 40 extra “Nightingale” courts.
He said the extra courts would “conduct jury trials”, helping to tackling a crown court case backlog that has topped 51,000.
The MoJ believes it could take until March 2023 to bring the crown court backlog back to pre-pandemic levels.
Announcing the opening of the new MoJ courtrooms, courts minister Chris Philp said: “We remain committed to exploring every viable option for additional court space, across the country – and that of course includes looking closer to home.
“Courts staff have gone to great lengths to help our recovery and the additional capacity at Petty France will further help to deliver speedier justice in the capital.”