With Labour still picking over the causes of its worst electoral performance since 1935, the man who led the party to three successive election victories warns the party it must "renew itself as the serious, progressive, non-Conservative competitor for power... [or] be replaced". Tony Blair presents research undertaken in three marginal constituencies, in the run-up to the election, suggesting it cannot begin the "long journey" back to government without "discarding the sectarian ultra-left politics" it says have taken over the party.

His intervention comes as Shadow Brexit secretary Sir Keir Starmer tells the Guardian the party must return to being a "broad church", including those who consider themselves "Blairites". But he praises Momentum - the "grassroots" movement that backed Jeremy Corbyn - and argues against steering away from a "bold and radical" agenda. Sir Keir says he is "seriously considering" a leadership bid, as is Wigan MP Lisa Nandy. Though that process will not start before January, we look at some of the early contenders. On Tuesday night, Mr Corbyn took responsibility for the election defeat at a meeting of MPs characterised by one veteran MP as a mixture of "anger, despair and denial".

"Am I a guinea pig?" says cancer patient Karen Childs. "It's quite nerve-wracking." She is the first person in the world to undergo "acoustic cluster therapy", which targets chemotherapy at tumours, in her case in the liver. The method uses ultrasound waves to pump microscopic clusters of injected drugs into tumours. Doctors at the Royal Marsden Hospital, in London, hope it will mean the drugs attack fewer healthy cells nearby and lead to fewer side effects for patients. Find out how it works in the BBC's exclusive report.

Ahead of an impeachment vote that could force Donald Trump to undergo a trial in the Senate, the US president uses a six-page letter to attack the Speaker of the lower House of Representatives. Impeachment is a political process to remove a president accused of misconduct. But Mr Trump accuses Nancy Pelosi, a Democrat, of "cheapening the very ugly word" and declaring "open war on American democracy" via the process. We pick out five key passages from the letter. To get up to speed with the case, check out our basic guide, and find out what it takes to remove a president.

Front pages feature a variety of stories, with some focusing on Labour's electoral woes. Leader Jeremy Corbyn was  "savaged" by MPs during a meeting, where his assertion that the election result "was ultimately about Brexit" was met with anger, says the Times. The Guardian hears exclusively from Sir Keir Starmer, the shadow Brexit secretary, who in saying he is "seriously considering" standing to be leader, argues "the case for a bold and radical Labour government" remains strong and the party should "anchor" itself in that.

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