Wes Streeting vowed yesterday to follow his predecessor and quit as Defence Secretary if Labour does not increase military spending.
He said he would leave the job he has held for just days 'as a matter of principle'.
John Healey resigned from the role over Sir Keir Starmer's failure to commit to spending 3 per cent of GDP on defence by 2030.
Asked if not meeting the pledge was also a resignation issue for him, Mr Streeting said: 'Absolutely.'
It came as the new Prime Minister refused to be drawn on a timetable for increasing spending to meet the 2030 goal in a Panorama interview to be broadcast tonight.
