The shadow justice secretary has attacked plans to give prisoners the right to vote.
Sadiq Khan said the government's proposals are "a slap in the face for victims of crime".
"MPs on all sides of the House and the public are right to be angry about this decision," he said.
"But they should also be angry at the manner in which it was announced - sneaked out on the day parliament broke up for Christmas."
Last year the coalition government conceded that it would have to follow a 2004 European Court of Human Rights ruling that the UK's automatic blanket ban on sentenced prisoners voting was in violation of the European Convention on Human Rights.
In November Cabinet Office minister Mark Harper told the Commons:
"This is not a choice, it is a legal obligation.
"Ministers are currently considering how to implement the judgment, and when the government have made a decision the House will be the first to know."
However, details were released in a written answer just before the Christmas recess.
Prisons minister Crispin Blunt told Labour MP Gavin Shuker that there are 5,991 inmates were serving less than four years for violence against another person.
In 2005 the Labour government appealed against the decision but the European Court's ruling was upheld.
Government lawyers advised coalition ministers that the government could face millions of pounds of compensation claims unless it complied.
The government will introduce legislation this year giving any prisoner serving a sentence of less than four years will be eligible to vote.
According to ministry of justice figures, nearly 29,000 offenders in England and Wales will be eligible.
However, prisoners will only be able to vote in EU and Westminster elections and will have to register at a home address and not the prison.
Judges will also be able to remove the right to vote from people sentenced to less than four years.
A Cabinet Office spokesman said: "We believe drawing the line at prisoners serving less than four years is enough to meet our legal obligations but goes no further than that.
"It ensures the most serious offenders are excluded."