Syrian President Bashar al-Assad, who has been in power for 21 years, has submitted his candidacy for next month's presidential election, state media said Wednesday. 

The 55-year-old is widely expected to secure a fourth term in office by a comfortable margin in the May 26 vote, which observers have already said would be far from free and fair.

"Parliament was informed by the high constitutional court that Bashar Hafez al-Assad has filed a request" to run in the upcoming poll, the official SANA news agency said.

Five other candidates have so far filed applications with the high constitutional court, it said.

The little-known contenders include a former lawmaker and several businessmen.

Presidential hopefuls have until April 28 to put forth their candidacy for the second such vote to be held since the start of the country's civil war a decade ago.

They will have to garner support from at least 35 members of the 250-seat parliament, which is dominated by Assad's Baath party.

They must have lived continuously in Syria for at least 10 years, meaning that opposition figures in exile are barred.

The previous presidential election was held in 2014 and saw two candidates run against Assad after a constitutional amendment allowing for a multi-candidate ballot.

Only two other candidates were approved by the Assad-appointed constitutional court and the incumbent won with 88 percent of the vote.