His colleagues in the campaign for a strong Lok Pal Bill, Kiran Bedi and Arvind Kejriwal, also slammed Sibal, who, however, denied having made any such statement and that he was with Hazare for drafting a strong anti-corruption legislation.
The 73-year-old social activist, who fought a successful battle for constitution of a 10-member committee of ministers and civil society representatives, said "If Sibal feels that nothing will happen due to the Lokpal Bill then he should resign from the joint committee as soon as possible."
Before leaving for his village Ralegaon Siddhi in Maharashtra, he told reporters "Why is he (Sibal) wasting his and our time? He should do other things for the country. Why does he want to be in the committee.
"If you believe that nothing will happen, you should not be there in the joint committee, he should resign and do some other work."
The Committee, chaired by senior minister Pranab Mukherjee, is to hold its first meeting on April 16 and is expected to come out with its draft of the Bill by June 30.
Sibal had yesterday told a public meeting here, "I ask this question. If a poor child does not have any means for education, then how will Lokpal Bill help? If a poor man needs help for medical services then, he will call up a politician.
How will Lokpal Bill help."
Asked about Hazare`s demand, Sibal told reporters today that he was with the Gandhian and that he wanted the Bill to be drafted as early as possible and to be effective in tackling corruption everywhere.
Clarifying his yesterday`s remarks, he said what he had meant was that "the scope of the Bill is different. The problems of the common man are different."
"I said that if you want to educate children, then this has no connection to Lokpal. If there is no water...
Lokpal is only connected to corruption and we will bring a good bill that will stop corruption."
He said they would sit with Hazare and bring out a bill so that the objective will be realised.
Bedi said Sibal should not waste the time of other committee members if he had no faith in its efforts. "Then it is better for him to withdraw from the committee," she said.
Activist Arvind Kejriwal said Sibal should not have made "sweeping" statements on the Lokpal which were raising doubts about the "seriousness" of the government in bringing in the legislation.
Kejriwal said "If you are not getting ration due to corruption, then you can get relief from this Lokpal. If you are not getting admission in a school, you can get some relief.
"But if there is no school, then Lokpal will not help you. It is a different domain and government has to do it," he said adding the legislation is meant only for tackling corruption."
Questioning the sincerity and seriousness of the government on the issue, Kejriwal said, "Obstacles were put on even small issue like issuing a notification on the setting up of the joint drafting committee.
"Now how many obstacles they will put during the committee meetings, we don`t know. We have great fear. May be many more protests are needed," Kejriwal said.
He said when the legislation has people`s backing "Sibal cannot do anything".
The other minister Khurshid said a decision to videograph the proceedings of the Joint Committee Bill as sought by Gandhian Anna Hazare has to taken by the panel itself.
Responding to a question on the demand by Hazare to videograph and make public the proceedings of the Committee to ensure transparency in the drafting process, Khurshid said, "The Joint Drafting Committee is supposed to decide its own procedure. This procedure about making whatever happens there public or televising it, will be decided by the Committee itself.... I can`t comment on it as an individual."
He said the draft Lok Pal Bill was a "high priority" and it will be ready "very soon."
Asked whether the bill which seeks to create an Ombudsman will be effective in fighting corruption, he said, "The way we try to better ourselves in other facets of life, this will be done in politics also and this will be an important step in that direction."
But, he added, "Has God`s existence ended all the vices? We still have to tell good things to our children. We still have to build temples and pray."
Meanwhile, BJP waded into the controversy saying comments by ministers Sibal and Salman Khurshid, who is also a member of the committee, raises doubts over the government`s intentions on making an effective law.
Party spokesperson Nirmala Seetharaman said Sibal, who made controversial statements on 2G scam, was in the habit of saying something first and retracting it later.
"The kind of statements he is making does not not instill confidence," she said.
Seetharaman also faulted Khurshid for his statement and said the kind of statements coming from responsible ministers did not not look like they were "working for consensus".
Congress answered the criticism against the ministers saying "we should not not queer the pitch".
Party spokesperson Abhishek Singhvi said one should not not get into charges and counter-charges when a positive process has been set in motion.