Anna Hazare on Saturday morning left for New Delhi for his daylong token fast Sunday to protest the government's version of the Lokpal Bill.
He vowed that he would continue his fight for a strong Jan Lokpal Bill till his last breath.
"This is the second struggle for independence and we shall have to make many sacrifices," Hazare declared before a group of supporters who gathered to see him off to Pune, from where he will leave for the capital.
"I shall not rest till a strong Jan Lokpal Bill is enacted, I will fight till the last breath. If the government fails to enact the bill soon (from Dec 27), I shall go on indefinite hunger strike," said Hazare, who is now planning another long agitation for the legislation with the winter session of parliament currently underway.
Earlier this week, his medicos had advised him a couple of days' complete rest before the fast, but the activist appeared cheerful and fit Saturday morning.
Adopting an aggressive stance, Hazare on Friday attacked the centre and blamed Congress general secretary Rahul Gandhi for what he termed "a weak bill" tabled before the parliament.
Hazare will fast at Jantar Mantar. Earlier in August, Hazare sat on an indefinite fast and broke it only after parliament broadly agreed to three key demands of his civil society group to battle corruption.