Greek islanders are threatening to hold a referendum on whether to veto proposals by the country's international lenders to scrap a reduced rate of value added tax for the islands, a regional governor said on Tuesday. Plans to increase VAT have been a sticking point in talks between the Greek government and its European and International Monetary Fund creditors, as the two sides try to hammer out a cash-for-reforms deal to unlock further aid. Yorgos Hatzimarkos, governor of a south Aegean cluster of islands that includes popular destinations such as Mykonos and Santorini, said his region had decided to hold a referendum with the backing of Finance Minister Yanis Varoufakis.