Angela Rayner, Britain’s deputy prime minister resigned on Friday after an investigation found she breached the ministerial code by underpaying on a property tax.

Rayner, a figurehead among the party’s left-wing base had on Wednesday admitted not paying enough on the flat purchase in southern England disclosing that she had saved £40,000 ($53,000) by removing her name from the deeds of another property and referred herself to the government’s independent ethics adviser.

In a letter to Starmer, ethics chief, Laurie Magnus, wrote that Rayner had failed to “heed the caution” of legal advice she had received and had therefore breached the ministerial code.

“Given the findings, and the impact on my family, I have therefore decided to resign,” Rayner wrote in a letter to Starmer, adding she would also be stepping down as housing minister and deputy leader of the Labour Party.

“I deeply regret my decision to not seek additional specialist tax advice,” Rayner said, adding she took “full responsiblity for this error”.

In his reply, Starmer told her he was “very sad” to lose her from government, but added: “You will remain a major figure in our party”.

Magnus said Rayner had “acted with integrity and with a dedicated and exemplary commitment to public service” but concluded he considered the “code to have been breached”.

Rayner had often been tipped to become Labour leader one day and has been a top target for political attacks by the Conservatives and right-wing media.