Keir Starmer has launched a bullish defence of his embattled deputy, Angela Rayner, after the chief constable of Greater Manchester police said she was facing investigation “over a number of assertions”. The Labour leader told MPs on Wednesday he believed the accusation that Rayner lied about her primary residence to avoid tax was a “smear”. While Starmer has largely tried to avoid commenting on the controversy in recent weeks, he tackled the issue head-on during a session of prime minister’s questions during which the two party leaders traded personal attacks. Responding to comments by Rishi Sunak that the Labour leader should read Rayner’s tax returns rather than Liz Truss’s memoir, Starmer replied: “We’ve got a billionaire prime minister and a billionaire peer, both of whose families have used schemes to avoid millions of pounds of tax, smearing a working-class woman.” Starmer’s comments came hours after Stephen Watson, the chief constable of Greater Manchester police, said Rayner was under investigation on a number of accounts. Rayner has been accused of potentially breaching the Representation of the People Act 1983 for providing false information to the electoral register about where she was living. But prosecutions must be made within 12 months of an alleged offence. She has faced scrutiny about whether she paid the correct amount of tax on the 2015 sale of her Stockport former council house because of confusion over whether it was her main residence. The allegations relate to her living arrangements during the first five years of her marriage, before she was elected as an MP in May 2015. Watson told BBC Radio Manchester: “I’m going to say very little about this because in truth we don’t give running commentaries on live investigations. However, I know that it’s very topical. “All I would say is, in line with what we have put out publicly, there are a number of assertions knocking about. I don’t need to tell people that. “That is a neutral act. It does not imply that the information gives us any hard and fast sort of evidence upon which to base anything at this stage. It is simply: we have an allegation, these allegations are of course all over the news, we are going to get to the bottom of what has happened.” A Labour spokesperson said: “Angela welcomes the chance to set out the facts with the police. We remain completely confident that Angela has complied with the rules at all times and it’s now appropriate to let the police do its work.” Sources close to Rayner have said it is unclear what the force is investigating. On Monday, the Conservative MP for Bury North, James Daly, said the police should be allowed to do their work, when asked on the BBC’s Politics Live show what crime he thought Rayner had committed and for more detail on what information he had provided to the police. Daly said: “Greater Manchester police are looking at a number of different offences and will investigate fully, and we should give them the time and opportunity to do that.” A police source told the Times that officers were looking at Rayner’s council tax arrangements after claims she was not living at her property. A police source told the newspaper the inquiry was “well-resourced”, with at least a dozen detectives, and that officers were looking at more than “a single issue”. A spokesperson for Greater Manchester police said on Wednesday: “Investigations are ongoing and we won’t be commenting further until they have been completed.” Rayner on Friday pledged to step down as deputy leader of the Labour party if a police investigation found she had committed a crime. She said: “I’ve repeatedly said I would welcome the chance to sit down with the appropriate authorities, including the police and HMRC, to set out the facts and draw a line under this matter. I am completely confident I’ve followed the rules at all times. “I have always said that integrity and accountability are important in politics. That’s why it’s important that this is urgently looked at, independently and without political interference.”