And almost as soon as the prime minister had finished explaining his decision, news filtered through that his deputy leader for the last 13 years would be following suit.
In an open letter to his East Hull constituency members Mr Prescott confirmed the decision he had revealed at last year's Labour party conference in Manchester.
"Tony and I were elected together back in 1994 and it has been an honour to serve as deputy to the most successful Labour prime minister ever," Mr Prescott said.
"To have been deputy leader and the longest serving deputy prime minister is a matter of great pride to me.
"This government is testament to the fact that it is possible to apply traditional Labour values in a modern setting. I passionately believe that it will continue to do so under a new leader and deputy, and that we have the values to convince the British people that we deserve a fourth term in government."
Commenting on the decision, Peter Watt, Labour party general secretary, paid tribute to a man who has so far spent 37 years as an MP.
"John Prescott has been a superb deputy leader," Mr Watt said.
"He is first and foremost a 'party man'. As general secretary, it has been a pleasure to work with 'JP'. He has never shied away from making sure that the party's view is represented at the highest level and he always stands up for what he believes in.
"I know how proud John is of what this Labour government has achieved in the past ten years: 2.5 million jobs created; a national minimum wage; two million council tenants now living in a decent home; a doubling of the international aid budget, to name but a few."
The race for the deputy leadership is likely to be a far fiercer one than for the leadership itself – which chancellor Gordon Brown is widely expected to win – with six senior figures having declared already.
Left-winger Hilary Benn; party chairman Hazel Blears; Mr Blair's former deputy political secretary John Cruddas; Northern Ireland secretary Peter Hain; constitutional affairs minister Harriet Harman; and education secretary Alan Johnson have all said they will be running to succeed Mr Prescott.
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