Number 10 has insisted that Sir Keir Starmer has "full confidence" in David Lammy.
It follows the deputy PM and justice secretary standing in for the PM at deputy prime minister's questions (DPMQs), where he refused to answer a question five times, telling the Tory opposite to "get a grip".
Shadow Defence Secretary James Cartlidge asked Lammy five times if any other "asylum seeker offenders" had been wrongly released, following convicted sex offender Hadush Kebatu being mistakenly let out of prison last month.
Lammy didn't answer the question, instead attacking the Conservatives' record in government on prisons.
"I have not witnessed a more shameful spectacle, frankly, for what the party opposite left in our justice system. Their criminal negligence on his watch," he said.
But seconds after PMQs ended, it was confirmed that a second foreign offender has indeed been released mistakenly - and has actually been on the run for a week.
Speaking to journalists following DPMQs, a spokesperson for Number 10 insisted that Starmer has "full confidence" in Lammy for his performance, and declined to give him a mark out of 10.
"I'm here to answer Questions and not give appraisals", the spokeserson said.
"The deputy PM stepped in today and answered questions and the PM is grateful to him for his work."
The spokesperson also refused to say if Lammy knew about the wrongly released prisoner before PMQs, and repeateldy pointed journalists to the Ministry of Justice and the Metropolitan Police, who were informed by the Prison Service that the man is missing.
They said the prime minister is being "kept updated".