ATHENS (Reuters) - Greece's government wants to resume talks with the country's international lenders immediately to clinch a deal to keep it afloat, Greek government spokesman Gabriel Sakellaridis said on Sunday. "The negotiations which will start must be concluded very soon, even after 48 hours," Sakellaridis told Greek television after opinion polls showed the 'No' vote with a clear lead in Sunday's referendum on a bailout proposal from creditors. "We will undertake every effort to seal it soon." (Reporting by Karolina Tagaris; Writing by Renee Maltezou)