A group of creditors has demanded payment on a US$ 1.5 billion Venezuelan bond that is in default, their lawyer said on Monday, kicking off a long-awaited showdown between creditors and the crisis-wracked OPEC nation. President Nicolas Maduro’s government and state-owned companies owe nearly US$ 8 billion in unpaid interest and principal following this year’s default on bonds amid a hyperinflationary collapse of the country’s once-wealthy socialist economy.