By Michele Kambas ATHENS (Reuters) - Prime Minister Alexis Tsipras has easily clinched parliamentary approval of his desired July 5 referendum on Greece's creditors' latest bailout terms. On top of that, the only information many Greeks have about the creditors' offer has been gleaned from leaks in the media since Greece's government has not published the proposal. "Basically they are asking us if we should stay or leave Europe." AN UNEXPECTED TWIST When Tsipras unveiled the referendum in the early hours of Saturday, he said he wanted Greeks to decide whether to accept or reject final terms that creditors had offered.