BUENOS AIRES - Argentina's peso lost 14 percent of its value against the dollar when exchange markets opened on Monday after President Mauricio Macri suffered a crushing defeat in party primaries over the weekend.

The peso opened at 53 to the dollar having closed on Friday at 46.55.

Macri called a meeting with Central Bank president Guido Sandleris before the markets opened on Monday, while putting back his morning cabinet meeting to 3:30 pm (1830 GMT.)

On Sunday, center-right, pro-business Macri was dealt a huge blow in his bid for re-election in October when he polled 15 points less than center-left Peronist candidate Alberto Fernandez.

"The president cannot have peace of mind. The markets are giving warning that the government has put itself in a position it cannot respond to," Fernandez told Radio 10 on Monday.

Macri managed only 32 percent in the party primaries that effectively acted as a nationwide pre-election opinion poll as all of the recession-hit South American country's major parties had already chosen their presidential candidates.

"It hurts that we haven't had the support we'd hoped for," admitted Macri.

Fernandez scored 47 percent and if he was to repeat that result in the October 27 general election first round, he would win outright without need for a November run-off.

Argentina's electoral law requires a candidate to gain 45 percent for outright victory, or 40 percent and a lead of at least 10 points over the nearest challenger.

"We're going to begin a new stage. We always fix the problems that others create," said Fernandez to thousands of cheering supporters in Buenos Aires on Sunday night. -AFP