Liberia's Supreme Court has stayed next week's presidential run-off election until it considers a challenge to first round results by a losing candidate who has alleged fraud.

Third-place finisher Charles Brumskine's Liberty Party challenged the results of last month's vote, which set up a Nov. 7 run-off between former soccer star George Weah and Vice President Joseph Boakai.

The election is meant to usher in Liberia's first democratic transition since 1944 after long periods of military rule and a civil war that ended in 2003.

In a writ issued late on Tuesday, the court instructed Liberty Party and the National Elections Commission to file briefs by Thursday at the latest. It was unclear if the court would rule before Nov. 7.

"This is a big step in the right direction," Liberty Party Chairman Benjamin Sanvee said in a statement. "Thankfully, the Court recognizes the gravity of the issues, and has taken action in defence of the law and democracy."

Earlier this week, Boakai's ruling Unity Party announced it was backing the legal challenge. It accused President Ellen Johnson Sirleaf, one of its own members, of interfering in the Oct. 10 vote by holding private meetings with election magistrates before the Oct. 10 poll.

Johnson Sirleaf denied the meeting were inappropriate and international observers like the European Union and the Carter Center have said that they saw no major problems with the first round vote.

Weah, a former soccer star in Europe, won the first round with 38.4 percent of the vote to Boakai's 28.8 percent and picked up an important endorsement last week from former warlord Prince Johnson, who won 8 percent of the first-round vote .

Morluba Morlu, a senior official from Weah's CDC party, said on Wednesday that he still expected the run-off to go ahead next week.

"It is sad for a ruling party that has been in power for 12 years (to) be crying," he said of Unity Party's support for the legal challenge. "We don't want any mockery of this election."