Conservative Argentine President Mauricio Macri suffered a resounding defeat in primary elections on Sunday.
The primary, in which presidential candidates from all parties take part, was won by his left-wing rival, Alberto Fernández.
Mr Macri, whose austerity measures have turned many voters against him, is hoping to win a second term in office in the presidential poll on 27 October.
But analysts say his chances of beating Mr Fernández now look very slim.
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