The government of Prime Minister Lawrence Gonzi lost its one-seat majority in the Maltese parliament on Thursday when one of its members of parliament quit the ruling Nationalist Party.
However, Jeffrey Pullicino Orlando handed the government a lifeline, saying he would continue to collaborate with the government.
“"I will, out of respect for the clear mandate the people honoured me with, continue to collaborate in the implementation of the measures outlined in the PN electoral programme for 2008," Pullicino Orlando told Gonzi in a resignation letter.
He said he could no longer work within the party, which, he said, had been "taken over" by Richard Cachia Caruana - Malta's former permanent representative to the European Union and a long-time consultant to Gonzi and former prime minister Eddie Fenech Adami.
Earlier this month, Pullicino Orlando backed a motion moved by the Opposition Labour Party against Cachia Caruana, forcing him to resign his EU post.
The party subsequently banned Pullicino Orlando from seeking re-election under its banner. He had already said he would not seek re-election.
Gonzi said the government intended to continue for the rest of its five-year term, due to end by March next year.
Opposition leader Joseph Muscat, who has a healthy lead in opinion polls, said Gonzi should put duty before power and call an election.