LONDON — Somehow, it keeps getting worse forKeir Starmer. The British Prime Minister was already in the mire: His economy is barely growing, ascendant criticsassail him from the left and right, and his popularity has tanked to historic levelsjust a year after a landslide victory. And on Friday Starmer suffered perhaps his most significant setback yet when his influential deputy resigned after admitting she underpaid 40,000 pounds (around $54,000) in property taxes. Angela Rayner, 45, has not always agreed with Starmer but has beena key figure in his Labour Party, seen as a counterweight voice for its disgruntled left-wing against their leader's centrist conservatism. After months of press speculation, Rayner admitted this week that she failed to pay enough property taxes — known as "stamp duty." She said she believed she had followed the rules, and was tripped up by her "complex living arrangements," including her 2023 divorce and son with special educational needs. All this played out while she served as the government's housing secretary as well as its deputy leader. She referred herself to the independent adviser on ministerial standards, Laurie Magnus, who acts as a watchdog appointed by the prime minister. Rayner promptly resigned her role as deputy prime minister and housing minister after his report was delivered Friday. "I take full responsibility for this error," she said in a letter to Starmer, accepting she "did not meet the highest standards in relation to my recent property purchase." She said that while "it was never my intention to do anything other than pay the right amount," she "must also consider the significant toll that the ongoing pressure of the media is taking on my family." Magnus' report agreed that Rayner had acted "in good faith," believing that she was paying the correct amount of tax during the purchase of her 800,000 pound seaside apartment in Hove, on the south coast of England, in May. However he said that Rayner broke the Ministerial Code (a set of rules and standards for people in the government to follow) because she did not follow her solicitors' advice to seek specific tax guidance. Had she done so, Magnus said, she would have known the correct amount was 70,000 pounds rather than the 30,000 she paid. "I believe Ms. Rayner has acted with integrity and with a dedicated and exemplary commitment to public service," he said. But he faulted her "unfortunate failure" to pay her taxes correctly, particularly given she was minister for housing at the time. Tax experts say Rayner will likely now face a fine of up to 12,000 pounds from His Majesty's Revenue and Customs, Britain's tax authority. In a handwritten note, Starmer said he was "very sad" that Rayner's tenure had "ended in this way," but said it was "right" that she had acted on the conclusion of her ethics report despite knowing it was "very painful" for her. Kemi Badenoch, leader of the opposition Conservative Party, reacted to her resignation by accusing Starmer of having "no principle, no backbone" and saying that "questions remain" about what he knew, and when. Just 14 months ago,Starmer won a historic landslide victoryagainst a Conservative Party whose 14-year rule had ended in scandal and widespread public disdain. But polls suggested that his victory owed as much to his opponent's toxic image as any ringing enthusiasm for his own platform. Whereas his predecessor as party leader,Jeremy Corbyn, had sought to take Labour back to its leftist roots, Starmer was more in the mold of Tony Blair: relatively progressive social values mixed with economic conservatism that critics say departed little from his right-wing opponents. That alleged caution has been met with opposition from multiple sides. Many on the left see him as maddeningly unimaginative in the face of a long-term economic malaise that they say requires radical, progressive action. And the right see him as too soft on immigration, most notablythe "small boats" crisisthat continues to see tens of thousands of asylum seekers cross the English Channel each year. Immigration is now the top priority for voters, polls show, andopinion surveys are now led by Nigel Farage, the friend and ally of American President Donald Trump, who leads the Reform political party. If he becomes prime minister after the next election scheduled for 2029, Farage has promised to enact a mass deportation scheme removing 600,000 undocumented migrants from Britain. A teenage mother who grew up in socialized housing in the northern town of Stockport, Rayner is widely seen as holding an everyman touch that resonated with voters in a way Starmer never has. She was viewed as a vital weapon in Labour's defense against the rising working-class anger being so successfully harnessed by Farage — and therefore her exit represents a powerful loss for the government. Rayner's departure is doubly significant because she also quit from the role of deputy party leader, which is chosen by the party members, rather than Starmer himself. This means a more outspoken left-wing lawmaker could be voted into the role — increasing the pressure on Starmer to veer left in search of a solution.