Debt-heavy Portugal is waiting to find out whether it will continue being eligible for vital financial help from the European Central Bank.

International ratings agency DBRS is due to announce Friday whether it is keeping its investment grade classification for Portugal's sovereign debt. Toronto-based DBRS is the only main agency that does not rate Portuguese bonds as junk.

The ECB, which is buying eurozone members' bonds as part of an economic stimulus program, can continue providing that help only if countries have at least one investment-grade rating.

Analysts expected DBRS to leave Portugal's rating unchanged, but the tension underlined doubts among economists and eurozone officials over the anti-austerity strategy of Portugal's new Socialist government, which is in power due to the backing of the Communist Party and radical Left Bloc.