Keir Starmer has questioned why Roman Abramovich has not faced UK sanctions over the Russian invasion of Ukraine, as Boris Johnson appeared to accept a Labour offer to strengthen a new bill cracking down on illicit assets. At a prime minister’s questions that began with the rare sight of MPs standing in unison to applaud the Ukrainian ambassador, Vadym Prystaiko, who was watching from the public gallery, Starmer repeatedly called for tougher action against Russian oligarchs. He began by citing comments made to the Commons last week by the Labour MP Chris Bryant, who referred to what he said was a leaked Home Office document that accused Abramovich, the Chelsea football club owner, of having links to the Russian state as well as to “corrupt activity and practices”. The Labour leader said: “Last week the prime minister said that Abramovich was facing sanctions. He later corrected the record to say that he isn’t. Well, why on earth isn’t he?” After Johnson said he could not comment on individual cases, Starmer also called for action against Igor Shuvalov, formerly Vladimir Putin’s deputy prime minister, describing him as being among a group to have “dipped their hands in the blood of Putin’s war”. Noting that Shuvalov owns two flats in London through a company, Starmer said the only reason the real owner was known was because it was revealed by Alexei Navalny, the detained Russian dissident. “Transparency is essential to rooting out corruption,” Starmer said. “It should be built into our law, but it’s not. And I’m ashamed that we only know about Shuvalov’s Westminster flats because a dissident risked his life. Is the prime minister?” He called for tougher measures to be added to the government’s economic crimes bill, to be debated on Monday, and queried why a new register of property ownership would not apply to existing owners for 18 months. “Why are we giving Putin’s cronies 18 months to quietly launder their money out of the UK property market and into another safe haven?” Starmer asked. He also called for the bill to speed up previously mooted changes to tighten companies’ records: “Will the prime minister work with us to amend the bill, on Monday, to include the most basic reforms, like identity checks for directors?” Johnson defended what the government had done so far in terms of sanctions against Russia and those associated with it, saying: “The squeeze is growing and will continue to grow.” He said: “The whole house should be proud of what we have done. We have led the way on Swift, we have led the way on Aeroflot, we have led the way on freezing assets of banks.” He hinted he was willing to work with Starmer to help “whip aside the veil of anonymity” over who owned assets in the UK. “I’m delighted by the support that the right honourable gentleman is offering,” Johnson said. “If we can work together to make sure that we strengthen and accelerate the package, all the better.” Starmer said he would table relevant amendments for Monday, adding: “I am very pleased we can show that unity with the ambassador here watching us.” The prime minister said the government was preparing to publish “a full list of all those associated with the Putin regime”. However, speaking afterwards, Johnson’s official spokesperson was unable to give details of when such a list might be published. “Where possible we will publish further details so the public can see where we believe there are individuals who are benefiting from the regime.” He said a “significant proportion” of those on the list would probably end up facing sanctions.