Kuwait's top court has ordered prominent opposition leader Musallam al-Barrak to be released on bail ahead of a final decision on charges he insulted the country's ruler, the activist's lawyer has said.

The supreme court ordered the former politician to pay bail of $3,300 on Monday and set the next hearing in his case for May 18, Thamer al-Jedaei said.

"We're all very happy to see al-Barrak free, and we are hopeful that the court's ruling next month will be in his favor," Jedaei told the AP news agency.

"We're glad that he's out and can be among his supporters tonight."

The charges against Barrak stem from a speech he gave to tens of thousands of demonstrators in October 2012 protesting against changes to the country's electoral law.

The 58-year-old called on Kuwait's emir, Sheikh Sabah Al Ahmed Al Sabah, not to "drag the country into a dark abyss," and said the country risked becoming an autocratic state.

Barrak was subsequently sentenced to five years in prison by a lower court, but an appeals court overturned that verdict and issued a shorter two-year sentence in February.

Potent opposition

In the days following Barrak's arrest, protesters took to the streets in his hometown province of Jahra, southeast of the capital, Kuwait City, as protesters burned tires and fired flares at security officers.

Last month, a protest in Kuwait City in solidarity with Barrak turned violent when hundreds of his supporters defied government regulations and marched from Irada Square toward the parliament building nearby.

Riot police used batons against protesters, arresting at least a dozen people.

Kuwait, a wealthy, oil-rich monarchy where a 50-seat parliament is elected by its more than a million citizens, has a potent opposition that is pushing for constitutional alterations to curb the ruler's powers to appoint the prime minister from the ruling family.

The OPEC member nation prides itself on having the most free-wheeling political system of all the Gulf Arab monarchies, but it is illegal to insult the ruling emir.

Source: Agencies