Lord Blunkett insisted the Birkenhead MP's decision to quit the Labour whip called for a rethink of the "Corbyn project".
Mr Fields dramatically announced his decision to withdraw the Labour whip on Thursday as he accused his party leader of failing to get a grip of the anti-Semitism crisis engulfing the party.
In response to the long-serving MP’s decision, Lord Blunkett has issued a stark warning to Mr Corbyn.
Writing in the Daily Telegraph, he said: “What matters for the health of our democracy and the continuity of the existence of the Labour party, of which I have been a member for 55 years, are the actions taken and the quality of leadership from Jeremy Corbyn and his colleagues over the next seven days.
"Either Jeremy Corbyn can lead a party into gradual decline and irrelevance, or demonstrate that he can lead a party fit for Government.
“The choice is his."
In an attack on the Labour leader’s failure to live up to his 2015 campaign pledge of “a kinder politics”, the former minister called for a rethink of the "Corbyn project".
He said: “Frank Field's decision, and his concerns over both anti-Semitism and the behaviour of party members indicate a deeper malaise.
David Blunkett has warned Jeremy Corbyn Labour could become 'irrelevant' (Image: GETTY)
Veteran MP Frank Fields quit the