Chariot wants all 70 of its charity partners to accept less than its current 30p donation for each £1 ticket sold. The reduction would be temporary, until sales improve. It is understood that the company is offering charities a deal whereby the difference will be returned to them at a later date.
Chariot refused to reveal how much less it is asking charity partners to accept, because it is still discussing the terms with them.
Stuart Handley, its director of communications, said: "We are working closely with our charities, and they are broadly enthusiastic and supportive. Any changes will be short-term and no up-front payments will be made to us by charities."
Tim McDonald, chief executive of charity partner the Talking Newspapers Association, was supportive of the move. "If the donation is above zero, we welcome it," he said.
The lottery was launched in April with a promise to donate 30 per cent of its proceeds to charities.