The ratings agency cut its rating for Tunisia for the third time since the country's revolution in 2011. S&P Analyst Patrick Raleigh was quoted by Bloomberg News as saying heightened political tensions in Tunisia are posing risks to the country's reform efforts.
"Risks to Tunisia's transition to democracy have increased markedly in recent weeks," and have subsequently hurts its ability to "take corrective measures against a weakening economic and financial backdrop," he said.
Tunisian Prime Minister Hamadi Jebali resigned late Tuesday after he was unable to form a government.
Tunisia's revolution ended the 24-year rule of former President Zine el-Abidine Ben Ali and ushered Islamic party Ennahda to power. Political tensions in the country escalated after the early February assassination of Chokri Belaid. He was the leader of the Democratic Patriots Movement, a party that helped lead the country's Jasmine Revolution.
The World Bank in late January said it was a long way from approving loans for Tunisia.
"This will depend on the performance of the government's ongoing program to strengthen the business environment and to promote transparency and good governance," regional director Simon Gray said in a statement.