ATHENS, Greece (AP) — Greeks started casting ballots early Sunday in the closely watched bailout referendum, with opinion polls showing people evenly split on whether to accept creditors' proposals for more austerity in exchange for rescue loans, or defiantly reject the deal. Greek Prime Minister Alexis Tsipras is gambling the future of his 5-month-old left-wing government on the snap poll, called last weekend — insisting that a "no" vote would strengthen his hand to negotiate a better deal with the country's creditors, and a "yes" would be a capitulation to their harsh demands. The campaign was fought amid banking transaction restrictions on cash withdrawals to 60 euros ($67) per day and large queues forming at ATMs and the few bank branches opened to help pensioners without bank cards. Yale University political science professor Stathis Kalyvas said the Greek government will face daunting challenges no matter which way the vote goes. With speculation swirling on the referendum's impact on Tsipras' government, Greece's Deputy Prime Minister Yiannis Dragasakis denied media reports that he would accept to lead a new "grand coalition" government.