KUWAIT: Kuwaiti police cordoned off the country's top court on Tuesday ahead of an expected ruling on an electoral law that could serve as a catalyst for political protest in the major oil producing state.

While Kuwait has not experienced the mass popular uprisings seen elsewhere in the Arab world, tensions have grown between the government, which is dominated by the ruling family, and the elected parliament.

At the government's request, Kuwait's constitutional court is due to rule on Tuesday on the legality of the 2006 electoral law, which divides the country into five constituencies.

Opposition leaders say they are concerned the court will declare the law unconstitutional, opening the way for the government to redraw electoral boundaries to its advantage ahead of elections expected later this year or next.

Thousands of Kuwaitis held a peaceful protest rally outside parliament late on Monday ahead of the court decision. Some said they would protest outside the court during the hearing.

But police closed off the court complex in the centre of the capital, also preventing media from entering the site, a Reuters reporter at the scene said.

Media access to court hearings in Kuwait is decided at the judge's discretion, but the court complex is usually open to reporters.

The government says the purpose of the court appeal is to protect the outcome of future elections from possible legal challenges.

Opposition Islamist and tribal candidates performed strongly in Kuwait's February elections and formed a majority opposition bloc in parliament that raised pressure on the government.

While Kuwait has one of the most open political systems in the Gulf, the head of the ruling family, Emir Sheikh Sabah al-Ahmad Al-Sabah, has the final say in political matters.

Persistent political infighting has stalled investment in Kuwait, a key U.S. ally in the region and one of the richest countries in the world per capita thanks to its oil wealth and small population.