The government issued the notification disclosing the appointments by President Ram Nath Kovind on a day the Bar Council of India also joined issue, terming as "unjust and improper" the collegium "recalling and reviewing" its earlier recommendation of Jan 12.
The notification said they are being appointed with immediate effect from the date they assume charge.
The appointments come even as the collegium decision to reverse the earlier recommendation of elevating the Chief Justices of Rajasthan and Delhi High Courts Pradeep Nandrajog and Rajendra Menon respectively and instead pushing the names of Maheshwari and Khanna.
On Tuesday, Justice Sanjay Kaul of the Supreme Court had written to the Chief Justice Ranjan Gogoi with an objection against sidelining Nandrajog saying he was the senior most among the judges in the zone of consideration and a wrong signal would go out if he was passed over.
Former Delhi High Court judge Kailash Gambhir wrote to the President saying 32 judges were being superseded by the elevation of Khanna.