Andy Burnham will have to set out his stall to show how he will deliver on his promises, the BBC's political editor writes.

Westminster is a postcode whose currency is power – and power is shifting, quickly. Not only did Sir Keir Starmer set out a timetable for his departure but the biggest potential rival to Andy Burnham, Wes Streeting, folded and endorsed the former mayor of Greater Manchester. So not only did we learn that Sir Keir will soon be gone, but we got the strongest possible indication yet that it is highly likely to be Burnham who is his successor and possibly very quickly. The photographs of the new MP for Makerfield beaming in the presence of hundreds of Labour MPs sit alongside the images of Sir Keir and his wife, both emotional, in illustrating that brutal transfer of power. Take the sight of Chancellor Rachel Reeves at Burnham's event. She wasn't spotted earlier, outside her own home, 11 Downing Street, when staff and some senior ministers applauded the prime minister as he set out his resignation plans. Senior figures hope to retain big jobs in government and there is a new man to impress. Those making the case for retaining Reeves at the Treasury would point out that she has maintained the confidence of the markets and keeping her in post might help Burnham do the same. But others tell me it is highly unlikely he would keep her on, given how closely she is associated with Sir Keir's administration. Some whisper Streeting may replace her, although he denied to me he'd been offered the job by Burnham.