Keir Starmer has revived the controversy over No 10 lockdown parties, accusing Boris Johnson of breaking the rules and attempting to cover up “wrongdoing”.

       For the first time since the Ukraine invasion, the Labour leader turned his fire on the prime minister over the scandal – while stopping short of his previous demand for him to quit.

       Returning to domestic political issues, Sir Keir said the pandemic had left every family “touched by worry or tragedy”, yet they had “followed the rules”.

       “But, some – and one man in particular - felt that the rules just didn’t apply to him,” he told the Scottish Labour conference

       “I refuse to accept that. I refuse to accept the pain and sacrifice of so many British families being cheapened, or laughed at.”

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       Warning that “trust in politics is now at an all-time low”, Sir Keir added: “That’s inevitable, when we have a government that is misleading the public and covering up their own wrongdoing to save the prime minister’s job.”

       The speech appeared to be a calculated gamble that the public is ready to be reminded of the Partygate row, nine days after political divisions were put on ice by the shock of Russia’s brutal invasion.

       Mr Johnson is still waiting to hear whether he will be fined by the Metropolitan Police for breaching his own Covid rules and for the full Sue Gray report that will follow.

       A fixed penalty notice had seemed likely to force him out of Downing Street – but Conservative MPs are unlikely to seek to topple him while war rages in Ukraine.

       Sir Keir also urged his party to recognise that power will not fall easily into its hands at the next election, despite the unpopularity of Mr Johnson and his government.

       “Trust in us declined too,” he warned, adding: “Too many working people came to see us as far removed from their lives.

       “We put our priorities above theirs; our ideas as more important, than their experiences,” referring – without naming him – to Jeremy Corbyn’s leadership.

       Urging his party to leave behind “political purity”, he said: “Our duty to win does mean keeping our discipline.

       “Never losing sight of who it is that we need to convince – working people and especially those who voted for electoral opponents.

       “We can win and we can make change or we can pursue apparent political purity inside this party – but please, make no mistake, we cannot do both.”

       On Ukraine, the Labour leader again warned the public to be ready to make ‘sacrifices” to help confront what he called the “imperialist aggressor” in the Kremlin.

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       “But those sacrifices are as nothing, compared to the suffering of the people of Ukraine,” he told his audience in Glasgow.

       Putin “believes the West is too corrupted to do the right thing”, he said, adding: “So we must prove him wrong.”