ECUADOR will go to the polls again for a second round after authorities announced on Tuesday that the ruling left-wing party’s candidate narrowly missed winning the presidency outright.

The National Electoral Council (CNE) said Pais Alliance candidate Lenin Moreno had fallen a hair’s breadth short of the 40 per cent threshold needed to win Sunday’s presidential election — with more than a 10-point lead over his nearest rival.

CNE president Juan Pablo Pozo told reporters that with 95 per cent of the ballots counted it was “mathematically impossible” for the result to change and a run-off between Mr Moreno and right-wing opposition candidate Guillermo Lasso was unavoidable.

This is the first time since 2006 that a winner had not been declared on election night.

The wheelchair-bound socialist will now have to face the former banker again on April 2.

Mr Lasso’s supporters had protested outside the CNE headquarters in the capital Quito for days before the announcement was made, complaining about the length of the count, which lasted over 48 hours, and accusing the CNE of fraud.

“You went out on the streets to defend your will,” Mr Lasso said.

Following Tuesday’s announcement, accusations flew the other way with Pais former interior minister Jose Serrano claiming that more than 2,000 ballots had been identified with signs of tampering to Mr Moreno’s detriment.

“There are ballots that differ from those uploaded by scanner and that is what we are here to complain about,” he told a press conference.

CNE President Juan Pablo Pozo said later the complaint would be reviewed.