"I feel worried about the news (of Anna's proposed fast) and as a fellow social worker I feel worried about this," Thakkar said in a statement here.
"I consider Anna Hazare as an esteemed friend and a person dedicated to selfless service, but I would like to mention in all humility that I find it difficult to agree with his decision to go on fast and strongly urge him to change his decision," Thakkar said.
Anna's first fast outside New Delhi's Jantar Mantar in April had earned nation-wide support and forced the Centre to agree to form a joint committee to look into the matter, he said.
The main difference however remained that the prime minister and members of judiciary were not brought under the purview of the Lokpal. The bill has been introduced and all parties will give their opinions according to democratic norms, Thakkar said.
"We must see that the democratic institutions are respected and appeal that the draft bill should be allowed to pass through its prescribed course as even after this there will be scope for amendments," the Gandhian said.
"As a humble student of Gandhian thought, I thought he was most careful before resorting to fast and for him it was a last resort. In one of his writings Gandhiji makes a distinction between a fast and a hunger strike," Thakkar, the founder secretary of the Nagaland Gandhi Ashram said.