From Morgan Stanley
Note the talk of a PSI (bond tax):

5. Portugal: Portugal’s five-year bonds are trading at ~16%, right around the level where Greek bonds traded last April when Eurozone officials began to turn their attention to forcing losses on private sector creditors. The key area of concern in the market is a €9.7B bond maturing in September 2013 that is not covered by the country’s €78B bailout. Portugal needs ~€25B-€30B to fund itself through 2015. Portuguese officials hope that a pickup in market confidence will allow it to return to the bond market in time to refinance the 2013 bond. The Portuguese funding concerns have been widely discussed in the press. While there has been speculation that the country could be next in line for a debt restructuring, this outcome has been disputed by both Portuguese and troika officials.