Portuguese local media said two more government ministers are preparing to tender their resignation after Foreign Minister Paulo Portas resigned yesterday.

Reports said Agriculture Minister Assuncao Cristas and Social Security Minister Pedro Mota Soares will follow their CDS-PP party leader Mr Portas.

Prime Minister Pedro Passos Coelho told the nation that he did not accept Mr Portas' resignation and would continue to lead the government to ensure political stability and work to overcome the stalemate.

However, with no solution imminent, Portugal's bond prices slumped further.

Mr Coelho's decision puts the responsibility for the government's survival squarely on the shoulders of Mr Portas, who now has to decide whether to stay in his post or pull his rightist CDS-PP party out of the coalition.

Without the CDS-PP, the centre-right government would lose its majority.