Health Secretary Wes Streeting resigned from the government on Thursday, stating he has “lost confidence” in Prime Minister Keir Starmer’s leadership.  “It is now clear that you will not lead the Labour Party into the next general election,” Streeting told Starmer in his resignation letter, advocating for “the best possible field of candidates” to be considered moving forward. Streeting is tipped as a top contender to replace Starmer and is reportedly planning to launch a leadership contest against the Prime Minister. His office has not yet responded to TIME's request for comment. Richard Johnson, a senior lecturer in politics at Queen Mary University, tells TIME that although Streeting is “very politically ambitious,” there are some “big structural barriers” that could get in his way. “The biggest being that the Labour membership is more to the left than where Starmer or Streeting are, and to win the leadership, you've got to win over the membership,” he says.…