On July 23, 2007, Standard&Poor's Ratings Services revised its outlooks on its 'BB+' long-term foreign and 'BBB-' long-term local currency sovereign credit ratings on the Republic of Peru to positive from stable. Standard&Poor's also affirmed it 'B' short-term foreign and 'A-3' short-term local currency sovereign credit ratings on the republic. The positive outlooks are based on Standard&Poor's expectation that strong economic growth prospects over the medium term will continue to strengthen Peru's macroeconomic framework and diminish its main vulnerabilities, creating the foundation for the foreign currency rating to be raised to investment grade. However, political and social instability continue to constrain Peru's ratings and constitute the single major restriction to an investment grade rating.