Cubans were called to the polls on Sunday to elect members of their National Assembly, Cuba's unicameral congress, from among whom the communist island's leadership was to be chosen.

Cuba's new leaders will come out of a process marked by key uncertainties: Fidel Castro, Cuba's leader for almost half a century, is a candidate, but it is unknown whether he will seek to become head of state once again.

Castro, 81, temporarily gave up power to his brother, Raul, in July 2006, in order to undergo surgery for an intestinal problem. He has not returned to power or been seen in public since, and admitted this week that he lacks the "physical ability" necessary to appear in public.

Cuban legislation establishes a maximum period of 45 days for the National Assembly to hold its first meeting after the vote. In its first session, members of the Council of State will be elected, and the role Fidel Castro envisages for himself will become known.

More than 8 million Cubans over the age of 16 were expected to elect their legislators and members of the country's provincial legislatures on Sunday.

Cuban authorities, led by the convalescent Castro, have called upon citizens to exercise the "united vote" - a formula that allows them to approve all candidates on the ballot by crossing just one box. This formula is tacitly understood as a show of support for the government.

Cubans go to the polls to elect 614 legislators from a list with the same number of candidates. Still it was possible the results would not be made public Sunday.

Cuban authorities argue that this system (in which each candidate could technically fail to obtain half the votes plus one and could thus be rejected) allows lesser-known candidates to stand the same chance as more "famous" ones, like Fidel and Raul Castro.

Critics say that this is no election at all.