Greece remains locked in talks with European creditors for the release of the latest tranche of its bailout loan, with the troika of international creditors demanding a list of economic reforms from the Tsipras government.
S&P notes that financial, business and economic conditions "have worsened due to the uncertainty stemming from the prolonged negotiations between the almost three-month-old Greek government and its official creditors."
The agency adds that "in our opinion, economic prospects could deteriorate further unless talks between Greece and its creditors conclude soon."
Greece has been given until the next meeting of EU finance ministers on April 24 in Riga, Latvia to put forward a reform plan to receive its next loan package.
Greek Minister of State Alekos Flambouraris told Greece's Antenna TV Wendesday that Greece can afford to wait out creditors, and that there is "no way" creditors will remain persistent with their original reform demands. Flambouraris added that Greece might consider a referendum on what to do next if the impasse fails to be broken.
Earlier this month, Finnish media reported that the Eurozone countries are drawing up plans in secret to exclude Greek from the Eurozone.
Greece's total debt to the troika of international creditors comprising the European Union, the European Central Bank (ECB) and the International Monetary Fund (IMF) amounts to about $270 billion.
Greek leftist government elected in late January managed to negotiate an extension of the bailout deal into late June 2015. However, the EU countries indicated that Athens had to propose a detailed list of reforms with some of them enacted into law to unlock next aid package.