Greece's finance minister has broken ranks with his prime minister over the country's planned referendum on its latest bailout package.

Evangelos Venizelos said the poll must not be a vote on Greece's future in the eurozone, and said new bailout funds must be released immediately.

Greece's prime minister and eurozone leaders have tied vote to whether Greece remains part of the euro bloc.

The issue is likely to dominate Thursday's G20 meeting in Cannes.

Mr Venizelos issued a statement in the early hours of Thursday after attending crisis talks with German Chancellor Angela Merkel and French President Nicolas Sarkozy.