The claim asserts a causal link: Labour MPs' resistance (the cause) has rendered the Prime Minister unable to act (the effect). While the phrasing is hyperbolic in its absoluteness—"will not let him do anything"—the underlying causal assertion is well-evidenced by the time of the June 2026 speech. Multiple independent sources document concrete instances where Labour MPs forced major policy reversals. In June 2025, Starmer was forced into a "dramatic climbdown" on his welfare bill, shelving planned PIP cuts after 49 Labour MPs voted against the second reading and over 120 had threatened to block it (Guardian, Independent, BBC). This followed U-turns on winter fuel payments and the two-child benefit cap, both attributed to backbench pressure (BBC, The Times). The BBC's political editor Chris Mason described the welfare climbdown as "the moment Labour MPs collectively realised they could push this government around," calling it "a massive loss in authority for Downing Street." The Spectator reported welfare was "the first of about a dozen U-turns" forced by the parliamentary party. The immediate context of Badenoch's speech reinforces the link: the May 2026 King's Speech contained no welfare bill. The BBC reported this omission was linked to the earlier rebellion, noting it "may be welcomed by some of those Labour MPs who forced the prime mer to back down last time" but would be seen as a sign of his "growing inability to drive an agenda." The Telegraph quoted the shadow chancellor saying Starmer was "terrified of his own MPs." A Labour minister, Zubir Ahmed, said the PM's authority had "irretrievably ebbed away," and nearly 100 Labour MPs had called for him to go. The causal mechanism is clear and repeatedly demonstrated: backbench rebellion → forced concession → erosion of authority → inability to advance agenda. The main caveat is the absolute wording—"do anything" overstates the case, as the government did pass other legislation (over 35 bills in the King's Speech). But the core causal claim, that his MPs are a decisive constraint preventing him from acting on key priorities, is strongly supported by official reporting, parliamentary records of rebellions, and contemporary analysis. Sources: BBC News – "Badenoch accuses Starmer of 'giving up' on welfare reform" (https://www.bbc.co.uk/news/articles/cgep3r9yg34o); BBC News – Chris Mason "The anatomy of Prime Minister Sir Keir Starmer's downfall" (https://www.bbc.co.uk/news/articles/ckg8kkdx7l9o); BBC News – "Keir Starmer u-turns on benefits changes after Labour backlash" (https://www.bbc.com/news/articles/cq6my6v81z4o); BBC News – "Welfare bill not included in government's King's Speech" (https://www.bbc.co.uk/news/articles/ckgplx9vzq2o); The Guardian – "Keir Starmer forced into dramatic climbdown to pass welfare reform bill" (https://www.theguardian.com/politics/2025/jul/01/welfare-bill-passes-after-keir-starmer-offers-late-concession); The Independent – "Starmer ditches Pip benefit reforms in face of Labour revolt" (https://www.independent.co.uk/news/business/keir-starmer-liz-kendall-rachel-reeves-government-pip-b2780634.html); The Telegraph – "King's Speech: Starmer leaves welfare reform out despite ballooning bill" (https://www.telegraph.co.uk/politics/2026/05/13/starmer-leaves-welfare-reform-out-of-kings-speech/); The Spectator – "Inside Keir Starmer's downfall" (https://spectator.com/article/authority-is-like-virginity-once-its-gone-its-gone-inside-keir-starmers-downfall/); Springer Nature – "Keir Starmer's statecraft: a critical appraisal of Labour in power" (https://link.springer.com/article/10.1057/s41293-026-00307-x).