But he has vowed to keep his own preferred candidate close to his chest out of fear of doing them "damage", he told a central London audience on Thursday.
In his strongest intervention yet in the race to succeed Mr Corbyn, the former leader said the party would need a "head to toe renewal" to win power again.
How would you renew the Labour Party? | The Nigel Farage Show podcast - Listen or read transcript on Metacast
