Ministers are reportedly considering restricting votes for prisoners to those serving 12 months or less.
According to the BBC, ministers are preparing to back down on plans to give the vote to all inmates serving less than four years in the hope of heading off a backbench revolt in the House of Commons.
The Cabinet Office, which is implementing the change in response to European court rulings, declined to confirm that a climbdown was in the offing.
But in a new statement, a spokesman said ministers were determined to do "the absolute minimum" to meet their legal obligations.
Prime Minister David Cameron has said that it was only with the greatest reluctance that he decided that some prisoners must be given the vote after the European Court of Human Rights found that the 140-year-old blanket ban was unlawful.
Failure to comply could cost tens of millions of pounds in legal costs and compensation, ministers warned. Some 2,500 inmates already have cases in motion.
But the prospect of granting the vote to more than 28,000 prisoners - including 6,000 violent offenders, 1,700 convicted of sex crimes and more than 4,000 burglars - sparked fury on Conservative backbenches when the four-year cut-off was floated last month.
Angry MPs will have a chance to revolt against the proposal in a few weeks' time, after Labour's former justice secretary Jack Straw and senior Tory David Davis secured a Commons vote on the issue. Cutting the maximum sentence under which prisoners can retain the right to vote to one year may see off a potentially embarrassing rebellion.
But it is almost certain to be tested in the courts, with the Government far from certain of victory.The Government will do the absolute minimum to meet its obligations and will ensure that the most serious offenders are barred from voting."
Shadow justice secretary Sadiq Khan said: "I am pleased that this government has undertaken this U-turn. "The Government should be standing up for the victims of crime but instead they are slashing police numbers and giving dangerous convicted prisoners the vote. I hope for all our sakes this is the first of many U-turns."