[Though the Convention has influenced the rulings of the court of Justice of the European Union, this was historically mostly because the EU Court wants to avoid confrontation with national courts like the Bundesverfassingsgericht over respecting rights, rather than some assumed desire to subordinate themselves to another court. Now the ECJ has to take into account Convention law under the Treaties, but this only applies to EU law - and why it's a bad thing that the ECJ should respect the ECHR has yet to be explained to me.]
The Court noted the state of the law in the 47 Council of Europe countries:
"Law and practice in Contracting States
33. According to the Government’s survey based on information obtained from its diplomatic representation, eighteen countries allowed prisoners to vote without restriction (Albania, Azerbaijan, Croatia, the Czech Republic, Denmark, Finland, “the former Yugoslav Republic of Macedonia”, Germany, Iceland, Lithuania, Moldova, Montenegro, the Netherlands, Portugal, Slovenia, Sweden, Switzerland and Ukraine), in thirteen countries all prisoners were barred from voting or unable to vote (Armenia, Belgium, Bulgaria, Cyprus, Estonia, Georgia, Hungary, Ireland, Russia, Serbia, Slovakia, Turkey and the United Kingdom), while in twelve countries prisoners’ right to vote could be limited in some other way (Austria, Bosnia and Herzegovina, France, Greece, Italy, Luxembourg, Malta, Norway, Poland, Romania and Spain).
34. Other material before the Court indicates that in Romania prisoners may be debarred from voting if the principal sentence exceeds two years, while in Latvia prisoners serving a sentence in penitentiaries are not entitled to vote; nor are prisoners in Liechtenstein."
The Court ruled that an indiscriminate restriction of the right to vote was contrary to the Convention. This doesn't mean that prisoners' right to vote cannot be restricted, but it has to be proportionate to the offence and not automatically applied to all prisoners regardless of the crime committed. I have heard few arguments against this per se, except that of the medieval concept of the civil death, where a prisoner looses all his or her civil rights upon conviction. The problem with this line of argument is that it hasn't been made in a very coherent way. The medieval concept entailed the loss of all rights - even that of the right to life, so that murdering such a person was not against the law (just like killing an animal isn't murder). Nobody is advocating that, but then that means that we distinguish between different types of punishment all the time. Some crimes result in a prison sentence, some do not. Much of the anger has been directed against the idea that murderers and rapists would get the vote - but this is not what the judgment is about, and the people in prisons are not solely murderers and rapists. Should I take it that serious violent crime is the sole criteria that people think would merit disenfranchisement, or are there other grounds?
Sadly, it has not been a subject of public debate to decide which crimes are worthy of disenfranchisement. It is a sad loss to the public debate, but it was raised by David Rennie of The Economist - the only place in the mainstream media I have read such an argument about the quality of this debate.
Jon Worth has looked at the international dimension to the idea of withdrawal from the Convention. Mutual responsibilities are important, and it's odd the way some people are eager to reject the argument that withdrawal would encourage other countries with worse human rights records to ignore the Convention or withdrawal as not the UK's concern (is it not in everyone's interest that their remains a culture of human rights and democracy in Europe? Like a garden, these things need to be maintained, and it's foolish to pretend that history is simply progressive and that things won't decline). The political culture in Europe and other European countries tends to spill over and become an argument in other countries, for good and bad. The argument that other countries should withdraw and take responsibility for these matters themselves - well, I don't find that convincing at all. I doubt that France's outburst over being called on the Roma expulsions was down to being part of a system of international law, but rather due to a feeling of entitlement, as if it should be allowed to do whatever it wants.
Similarly the attitudes of exceptionalism do not make good arguments for withdrawal. The idea that there is something unique about the UK that it will always deal with these matters well is not very reasuring. Likewise, I wouldn't believe France would be great at the job simply because it can claim that the Declaration of the Rights of Man and Citizen as part of its historical legacy. The UK's recent anti-terrorism laws have been a cause for concern for the UK courts, but some of these issues (unrestrained stop-and-search) had to reach the ECHR.
A claim that is also being made is that British judges can protect the rights of citizens better than the European Court. First of all, this ignores the fact that due to the doctrine of Parliamentary sovereignty, British judges cannot overturn breaches of human rights enacted by Parliament (say, if it legalised torture or restricted the franchise). Second, though it has been pointed out that some US states don't permit prisoners to vote, it's not a clear "continental European v the Commonwealth" dividing line, as Canada and South Africa have produced similar judgments. The question then becomes would the people who argue that the British judiciary should be able to protect rights accept it if the Supreme Court made the same judgment? Or is it more of an argument that it should be for the legislature rather than the judiciary (in which case it becomes a question of should the state be able to do what it wants - for no matter how democratic the decision is, it ultimately uses state power against the individual)? I'm afraid I've never been convinced by the argument that politicians should have absolute power.
Indeed, in a system where rights in general are conferred and may be taken away without reference to the rule of law it is hard to speak of rights as such. Surely the correct term for rights that are bestowed and may be taken away by an unchecked sovereign authority is "privileges"?