Keir Starmer's leadership was already under pressure. Then John Healey quit the UK government. As we sat down to get voters' verdicts on the Prime Minister in Makerfield, he suffered yet another massive headache – his Defence Secretary, John Healey, resigned over defence spending. And a few hours later, two more resignations followed. How weak is Keir Starmer now? And what does this row over defence spending mean for the safety of the UK? Beth Rigby, Ruth Davidson and Harriet Harman hear from