A decision over whether prisoners should be given the vote could delayed until after the next general election, the Justice Secretary has indicated.
Chris Grayling said complex recommendations made by a cross-party committee about how to deal with the controversial issue had caused delays, and refused to rule out kicking the issue into the next parliament.
The Tory last year published a draft Bill offering MPs three options - giving the vote to prisoners serving less than four years or less than six months or keeping the blanket ban.
After the recommendations were set out, a committee of MPs and peers recommended that voting rights should be given to p risoners serving short sentences or approaching the end of their time behind bars.
They said it would be ''wholly disproportionate'' for the UK to defy a ruling by the European Court of Human Rights, which has said Britain's ban on votes for those behind bars is a breach of their human rights .
The committee called on the Government to table a Bill granting the vote in local, general and European elections to those serving less than 12 months or within six months of release, with exceptions for those convicted of serious crimes.
Prime Minister David Cameron has made clear he does not want to extend votes to prisoners, telling MPs it would make him ''physically ill'', and a House of Commons vote in 2011 saw MPs vote by an overwhelming 234 to 22 to preserve the ban.
Quizzed by the House of Lords Constitution committee about the Government's progress, Mr Grayling said the committee's recommendation was the reason for the "slightly slow response".
He said: " The position we are in at the moment is we are still considering the response from the committee, and the reason that we are taking a bit of time over this is not that we have moved away from our earlier position but because the option that the committee recommended - which was to provide, or to be considered, providing votes for prisoners in the last few months of their sentence - actually is quite complex.
"So, we need to take quite a careful look at what the viability is of doing that. Obviously, I would wish, in whatever measures in due course are brought before the House, to be able to reflect the views of the committee, but it is not something where you can simply tick the box and say 'yep, fine'.
"It's actually quite different to anything that has previously been envisaged. It does require some careful analysis."
Asked if the delays meant the matter would probably be pushed beyond the end of the parliament, Mr Grayling replied: "I couldn't say that for certain yet. But it certainly wasn't a straightforward recommendation because, as you can imagine, we have got people at different stages of their sentence, we have got people who are on indeterminate sentences, and so looking at how exactly you deal with that, and of course, people who are subject to parole board release as opposed to automatic release again causes a logistical issue for us."
Mr Grayling told the committee it was Conservative policy to replace the Human Rights Act but insisted the details of how that would be done would be set out in the party's manifesto.