International pressure mounted on the Maldives Wednesday to go ahead with a presidential run-off election due this weekend which the Supreme Court has suspended.

Canada and Australia joined the Commonwealth and the US in calling the authorities to hold the vote on Saturday, as previously scheduled, with ex-president Mohamed Nasheed seen as the front-runner.

Canadian Foreign Minister John Baird urged Maldivian judicial authorities "to not unduly delay the expression by Maldivians of their democratic will," while Australia said it "hopes to see an early resumption of the electoral process".

Baird also condemned a reported pepper-spray attack on Nasheed during a protest following the Supreme Court's suspension of the run-off on Monday night.

The comments came as the court heard a petition by the third-placed candidate Gasim Ibrahim who claimed electoral malpractice in the first round of voting on September 7.

Nasheed won the round with 45.45 percent of the vote, which was found to be credible and fair by domestic and international observers.

He called for nation-wide "peaceful" protests on Monday and his Maldivian Democratic Party held a large rally in the capital Tuesday night, spokeswoman Shauna Aminath told AFP.

"About 5,000 people participated in the rally and it went off peacefully," she said.

The polls are seen as a test for the Maldives' young democracy 18 months after the violent ousting of Nasheed, who resigned in February last year following a mutiny by police.

Nasheed, a former pro-democracy campaigner, has railed against the country's judiciary before, which he sees as biased and intent on protecting the interests of former autocrat Maumoon Abdul Gayoom and a handful of tycoons who control the tourism industry.