A human rights court ruling against UK laws banning prisoners from elections does not mean all inmates will get the vote, the Lord Chancellor has said.
John Hirst had pleaded guilty to manslaughter
It comes after the European Court of Human Rights in Strasbourg said banning ex-inmate John Hirst from the polls had breached his right to free elections.
Lord Falconer said British legislation would be reviewed and some categories of prisoner might be allowed to vote.
But it would not be a "wholesale change" he told BBC News.
Mr Hirst, now released after serving 24 years of a life sentence for the manslaughter of his landlady, welcomed the Strasbourg ruling.
He told the BBC: "The European convention allows everyone to vote. It does not say 'everyone, bar prisoners'.
"It's always been the law. What we've had in this country is successive governments refusing to implement it.
"It doesn't matter how heinous the crime, everyone is entitled to have the basic human right to vote."
Mr Hirst first challenged the vote ban in the High Court but it rejected his claim that the Representation of the People Act 1983 was incompatible with the Human Rights Convention.
But the Strasbourg court ruled by a majority vote of 12 to five judges in his favour. It said his rights had been violated under the Convention on Human Rights, to which Britain is a signatory, which guarantees the "right to free elections" under Protocol 1.
The judges said this applies equally to prisoners, describing the voting ban as a "blunt instrument" which affected a significant category of people in a discriminate way.
Lord Falconer told BBC Radio 4's World at One: "I can make it absolutely clear that in relation to convicted prisoners, the result of this is not that every convicted prisoner is in the future going to get the right to vote."
He said it was possible the review would lead to certain categories of prisoner, convicted of lesser offences, being allowed the vote.
But he added: "This is not a wholesale change, this is simply the court saying `Consider carefully the basis of your law'.
"It could well be that, having considered it, it is a proportionate conclusion that all people who are convicted and sent to prison cannot vote."
Prison Reform Trust (PRT) director Juliet Lyon said: "Prisoners should be given every opportunity to pay back for what they have done, take responsibility for their lives and make plans for effective resettlement and this should include maintaining their right to vote."
Shadow attorney general Dominic Grieve said: "Giving prisoners the vote would be ludicrous.
"If convicted rapists and murderers are given the vote it will bring the law into disrepute and many people will see it as making a mockery of justice."
But the Liberal Democrats, who have supported the lifting of a ban on prisoners voting, welcomed the move.
Home affairs spokesman Mark Oaten said: "Today's ruling is not just about rights.
"It is about ensuring that prisoners return to their communities as responsible citizens."