(Updates with Spanish spokesman's confirmation)
BRUSSELS, April 27 (Reuters) - Euro zone leaders are discussing the possibility of holding a special summit in Brussels on May 10 to activate an aid package for Greece, a spokesman for the Spanish government said on Tuesday.
"There are talks at the highest level, and May 10 is the first available date after the vote for activation in the Greek parliament on May 6 or 7," said the spokesman, whose country holds the European Union's rotating presidency.
"The talks were already going on and have nothing to do with the downgrades by ratings agencies," the spokesman told Reuters.
Rating agency Standard and Poor's earlier slashed Greek debt to junk status on Tuesday and also downgraded Portugal, as investors worried political pressures could block a multi-billion euro bailout of Greece.