The polls predict an overwhelming victory for current president Marcelo Rebelo de Sousa, supported by the centre-right and the Christian-democrats. President Rebelo de Sousa also has the unofficial support of the general secretary of the Socialist Party and prime-minister António Costa.
Currently, the socialist party rules the country with a minority government, supported by agreements with the left parties, but lost the support of the left in the last budget vote.
José Palmeira is a professor of Political Science at the University of Minho in northern Portugal:
"I think that for the Socialist Party, it will be interesting if, despite everything, Marcelo Rebelo de Sousa does not have a great result so that he does not feel so reinforced, because this may cause an imbalance in the power relations between the presidency and the government," he said.
"The role of the President of the Republic may be further strengthened in the next term, if, for example, there is a political crisis. In scenarios of political crisis, in which it is necessary to replace the government before the end of the term, before the end of the legislature, the role of the President of the Republic is fundamental, as he has to mediate, so to speak, the formation of a parliamentary majority in support of the Government."
But with Portugal going through a new national lockdown, there are fears that turnout for the presidential election on Sunday could be even lower than in previous elections.
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