DAVID Cameron was last night called on to lift Britain's blanket ban on prisoner voting after the European Court of Human Rights ruled it was illegal and some inmates at least must be allowed to vote.

The development raises the possibility that the first ballot in which Scottish prisoners take part could be the independence referendum in autumn 2014.

In a landmark judgment on the case of an Italian prisoner's human rights, the court in Strasbourg ruled it was "up to member states to decide how to regulate the ban on prisoners' voting".

The judges said the decision amounted to confirmation of a ruling against the UK in 2005 that a blanket ban on all prisoners losing voting rights was a breach of their human rights.

The Prime Minister famously said that the idea of prisoners having the vote made him "sick to the stomach" but acknowledged non-implementation could prove very costly to the taxpayer.

Thousands of prisoners have made claims, which could amount to £160 mil-lion in compensation.

Mr Cameron and his colleagues now have six months to come up with their proposals and introduce fresh legislation.