UK prisoners seek right to vote in increasing numbers
There has been a sharp rise in the number of UK prisoners taking legal action to secure the right to vote.
The number now applying to the European Court of Human Rights has risen by 1,000.
All the cases are currently suspended while the government decides how to respond to the court's ruling that prisoners should get the vote.
It is thought the increase could be due to solicitors encouraging prisoners to apply for compensation.
At the end of 2010, Cabinet Office minister Mark Harper said around 2,500 cases were outstanding at the court in Strasbourg.
But this week in a written answer to shadow justice secretary Sadiq Khan he said that the figure had risen to 3,500.
While the government considers its position on the issue the ECHR is also deciding whether to reconsider the cases which prompted the ruling in the first place.
Last year, Prime Minister David Cameron told the House of Commons that it made him feel "physically ill" to think about giving the vote to anyone who was in prison.
On Tuesday, Mr Khan said the government's policy was "all over the place."
"The indecision we have seen from ministers is now plainly being exploited by prisoners. This was completely foreseeable and avoidable.
"The British public want straight answers from the government about which prisoners they intend to give the vote, under what conditions and according to what legal advice."
A Cabinet Office spokesman declined to comment in detail while legal cases are pending, but added: "No claims have been paid out and we are awaiting a decision from the European Court of Human Rights about whether they will be referring this to their Grand Chamber."