A lawyer for a Kuwaiti opposition leader says the country's supreme court has upheld a verdict and the two-year prison sentence against the former lawmaker on charges he insulted the country's ruler.

Attorney Thamer al-Jedaei told The Associated Press on Monday that his client, Musallam al-Barrack, will turn himself in once he receives formal paperwork from the court.

Al-Barrack was originally sentenced to five years in prison by a lower court, but the appeals court overturned that verdict and issued a shorter two-year sentence in February.

The case stems from a speech al-Barrack gave in October 2012 urging Kuwait's ruler Sheikh Sabah Al Ahmed Al Sabah not to "drag the country into a dark abyss" while charging that Kuwait risked becoming an autocratic state under new electoral laws.