As Prime Minister Antonis Samaras braces for the arrival in Athens on Friday of European Council President Herman Van Rompuy and officials representing Greece’s foreign creditors, who are to inspect a proposed blueprint for 11.5 billion euros in new austerity measures, it was clear on Thursday that he must also win round his own coalition.

Tensions were growing between the camps of Samaras and socialist PASOK leader Evangelos Venizelos despite reports that officials in the premier’s office had proposed a meeting with coalition leaders on Sunday afternoon when Finance Minister Yannis Stournaras is due to meet with visiting envoys of the European Commission, European Central Bank and International Monetary Fund, the so-called troika.

Both Venizelos and Fotis Kouvelis of the Democratic Left are reportedly insisting on meeting with Samaras to sign off on the austerity package for 2013 and 2014 before government officials present the blueprint to foreign envoys.

Samaras is to meet with Van Rompuy at 4 p.m. on Friday -- though the details of the package are not on the agenda of talks -- while his meeting with the troika is not due until Monday.

Coalition officials are still trying to iron out differences regarding the content of the package. Venizelos and Kouvelis object to some of the more onerous measures, with the latter reportedly proposing additional cuts to defense and health spending so that pension cuts can be softened.

Meanwhile Venizelos appeared to take issue on Friday with Samaras’s behavior, suggesting that the premier was acting without his coalition partners’ endorsement. “This is not a one-party government,” Venizelos said during an interview on Real radio station, adding that PASOK’s role within the government was “encouraging, supporting and monitoring.”

The parties in the coalition are seeing their support plummet amid increasing austerity, according to two new opinion polls that also show the far-right Golden Dawn gaining ground. According to a survey by VPRC poll for the Ellada Avrio newspaper, the main left-wing opposition SYRIZA is polling at 30 percent, compared with 28 percent for conservative New Democracy, which leads the coalition, while Golden Dawn is polling at 12 percent. Another survey for the left-wing To Pontiki weekly by the Pulse polling firm put ND and SYRIZA at 25 and 24 percent respectively, with Golden Dawn at 10.5 percent.