New Delhi: Cranking up pressure, Anna Hazare on Saturday wrote a fresh letter to the Prime Minister saying doubts have arisen over the passage of Lokpal bill in this Parliament session and threatened to go ahead with his proposed fast and 'jail bharo' agitation if it is not done.

Hazare alleged that the government's behaviour was "not at all right" and asked why Singh changed his stand on Citizens' Charter despite giving a written assurance that it will be part of the Lokpal bill.

The 74-year-old activist also questioned the rationale in keeping CBI out of Lokpal, saying that there is no point in having an ombudsman if it does not have its own investigating agency.

Alleging that the UPA has given assurances on Lokpal Bill but every time betrayed people, he said Singh in the past few months has assured him in writing that a strong Lokpal Bill will be passed in Parliament's Winter Session.

"We suspended all our agitations till Winter Session taking your word on face value. Reports published in media now say that the Winter Session will end on December 23. Will the Lokpal Bill be passed by then. We have doubts on this.

"...despite your promises, if a strong, independent and effective bill are not passed in the session, I will be forced to sit on a fast from December 27. Jail Bharo agitation will start from December 30," he said in his four-page letter.

Hazare appears to have pushed forward the date for the jail bharo agitation by two days as he had earlier announced that this mode of protest will be undertaken from January one if Lokpal Bill was not passed in the ongoing session of Parliament.

Demanding bringing CBI'a anti-corruption wing under Lokpal and making it its investigative agency, he said it appeared that no government wants to give away the control over CBI for political reasons.

"Does it mean that Lokpal will not have an investigative agency. Without an investigative agency what will it do? Then it is better that we don't need a Lokpal," Hazare said alleging whether it was Congress or BJP rule, CBI was misused.

Hazare said he was surprised to see the Union Cabinet clearing a separate Citizens' Charter on December 13 when Parliament has already passed a resolution in which it is clearly mentioned that it will be under Lokpal.

"You (Singh) yourself have written to me and now why are you changing your stand and say that it will be sent to the Standing Committee. That will take another four months. Don't you think that people are being cheated again and again," he said.

The activist also pointed out the Parliamentary Standing Committee recommendations on appointment of search and selection committee for Lokpal was fraught with deficiencies as politicians play a major role in it.

Hazare alleged that Parliamentary Standing Committee chairman Abhishek Manu Singhvi insulted Parliament by not taking into cognisance the resolution passed by the House.

"Out of the three issues -- inclusion of lower bureaucracy, Citizens' Charter and state Lokayuktas, two of them have not been accepted. If a Standing Committee Chairman ignores Parliament's resolution, what is the future of our democracy," Hazare said in the letter.

"The Standing Committee report (on Lokpal) is a betrayal of the countrymen," he said.