Keir Starmer announces he is resigning as the prime minister of the United Kingdom on Monday, according to the outlets provided. The reporting says his departure follows pressure and a “mutiny” or revolt within his own Labour Party, indicating internal disagreements over his leadership. In parallel, Donald Trump posts on Truth Social responding to Starmer’s time in office. The articles report that Trump criticizes Starmer, describing his tenure as having “failed badly.” The sources presented do not provide additional details on the specific causes of the reported internal party mutiny, nor do they include confirmation from UK officials beyond Starmer’s own announcement. No further information about Trump’s rationale or any policy disputes is included in the provided summaries. Overall, the accounts link Starmer’s resignation to reported internal party challenges and to Trump’s public reaction to the event.