A refusal to act on a ruling by the European Court of Human Rights that Britain's current ban on prisoner voting is unlawful would "undermine the standing of the UK," said a cross-parliamentary committee.
The committee wants prisoners who are nearing the end of their sentences to be able to vote and said the Government had failed to set out a "plausible" case for maintaining the existing blanket ban.
Prisoners serving short sentences or approaching the end of their time behind bars should be given the vote, a cross-party parliamentary committee has recommended.
The committee said it would be "wholly disproportionate" for the UK to defy a ruling by the European Court of Human Rights and said the Government had failed to set out a "plausible" case for maintaining the existing blanket ban.
It 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 particularly serious crimes.
Europe's Human Rights watchdog hit back today in the continuing war of words with London over voting rights for prisoners.
Prime Minister David Cameron is defying a Strasbourg court ruling that the UK's blanket ban on all prisoners voting while in jail is a breach of human rights.
But a draft Bill before Parliament - announced as a deadline expired for action to change the law - includes the option of keeping domestic rules unchanged.
The judgment is expected to be made in September 2013.
47 ministers on the Council of Europe have said the UK's plans for prisoner voting are not in line with the convention.
The committee of ministers in Strasbourg, which oversees the European Court of Human Rights, has confirmed continuing with the third option in the draft parliament bill on voting would breach the UK's obligation to enforce the court's decisions.