The prime minister has again refused to give more details on the resignation of his transport secretary over a fraud offence before she became an MP.

Keir Starmer repeatedly refused to elaborate on the “further information” that came to light leading to Louise Haigh stepping down last week.

Haigh resigned after it emerged she had pleaded guilty to a criminal offence related to incorrectly telling police that a work mobile phone was stolen in 2013. It is understood the incident was disclosed to Starmer when she joined the shadow cabinet.

During prime minister’s question time Starmer was repeatedly pressed by Conservative Party leader Kemi Badenoch to explain why he “knowingly appointed a convicted fraudster” to his cabinet.

Badenoch told the session: “The question today is what has been on the lips of all Labour MPs, including, I believe, the health secretary yesterday - the prime minister knowingly appointed a convicted fraudster to be his transport secretary. What was he thinking?”

“The country needs conviction politicians, not politicians with convictions,” she said.

But Starmer insisted he would not disclose private information, reminding the Tory leader that two of her predecessors had convictions for breaking Covid rules.

He highlighted the actions of previous Conservative party leaders, saying Haigh’s decision to resign was a “marked contrast” from Tories’ behaviour over the last 14 years.

“The previous transport secretary was right, when further information came forward, to resign - what a marked contrast from behaviour in the last 14 years,” he said.

Badenoch accused Starmer of “obfuscating”, adding: “But I’m going to keep him on the topic. He owes the house an explanation. He said that the former transport secretary was only asked to resign after further information came to light. What was that further information?”

Haigh was advised to resign by No 10 for a possible breach of the ministerial code, after she did not declare her spent conviction for fraud to the government when she became a cabinet minister.

Sources said Morgan McSweeney, Starmer’s chief of staff, delivered the message to Haigh on Thursday night that it would be best for her to step down.

They said Haigh had not declared the 2014 conviction for wrongly reporting a mobile phone stolen to the police because she was asked only about unspent offences. She had pleaded guilty to fraud by misrepresentation and received a conditional discharge.

Three sources said Haigh had told Starmer about the conviction when she became shadow Northern Ireland secretary in 2020.

However, Starmer’s official spokesperson refused to confirm on Friday whether the prime minister knew about the conviction at any point.

In 2022 Boris Johnson became the first prime minister to receive a criminal penalty while in office. During the Partygate scandal, he, his wife, and the then-chancellor Rishi Sunak received £50 fixed-penalty notices from Scotland Yard.

Fixed penalty notices are considered a criminal sanction but not a criminal conviction.