Main opposition leader Kyriakos Mitsotakis said he believes a "courageous debt restructuring" is necessary for Greece, something he said European creditors promised as far back as 2012.Speaking to a local television station on the large island of Crete, the New Democracy president also repeated that his party - which now enjoys double-digit percentage leads over ruling SYRIZA -- will not vote for any new austerity measures "or countervailing measures" brought by the leftist government."We need an expansion of the grace period (for repaying loans) and a reduction in interest rates. We know what is acceptable. When Mr. (Greek PM Alexis) Tsipras was demanding a write-off of the debt, he knew he was asking for something that could not happen; he was undermining the country's credibility. Of course, he's swallowed all of these (promises), he's forgotten them," Mitsotakis charged.