* Some 1,500 gather outside parliament
* Protest over possible changes to electoral boundaries
* Government wants top court to rule on the issue
KUWAIT, Sept 10 (Reuters) - Around 1,500 Kuwaitis took part in a rally late on Monday to protest against possible changes in the electoral law and call for more democracy.
The crowd, which included opposition lawmakers and political activists, gathered outside parliament in a square which has hosted several anti-government demonstrations since late last year.
Monday's turnout was smaller than previous rallies in the major oil producer and there was only a light police presence.
Kuwait's Interior Ministry said on Sunday it would act firmly against any "unlicensed" protests in the country and said calls for a sit-in at Erada Square undermined security and threatened public order.
While the U.S ally and OPEC member state has not had the kind of mass popular uprisings seen elsewhere in the Arab region, political tensions have escalated between the hand-picked government and elected parliament.
"Our problem is with the government. We like the emir, we all do," Suleman Mohammed, who is retired from the army, said.
"We want a little more democracy, more freedom, more rights."
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.
He chooses the prime minister who in turn picks a cabinet, with important positions held by al-Sabah family members.
It is a government appeal to Kuwait's top court which is at the heart of the latest political tension.
The cabinet has asked the constitutional court to rule on the 2006 electoral law which divides the country into five constituencies. It says the verdict is needed to protect the outcome of future elections from possible legal challenges.
But some opposition figures say this is a bid to abolish the current boundaries and gerrymander victory in elections expected this year or next. The court is due to rule on the government's petition later this month.
The court drew the anger of protesters earlier this year when it effectively dissolved the opposition-dominated 2012 parliament and reinstated a more government-friendly assembly.
"The government plays with our democratic system. There are people behind the government, controlling it," said a 33-year-old government ministry employee who gave his name as Abu Saad.
He said he was referring to divisions within the ruling family and competition between other powerful families.
"Kuwait is like a cake and everyone wants a piece," he added. "Twenty years ago Kuwait was number one in the region, there was no Dubai, no Qatar. Now it is in last place."
Years of political infighting have stalled investment in Kuwait, which is one of the richest countries in the world per capita thanks to its oil wealth and small population.
Speakers at the rally, who included Islamists and tribal members of parliament, renewed opposition calls for an elected government. Political parties are banned in Kuwait so lawmakers form blocs in parliament based around tribal ties and policy.
Turnout at the height of protests last year over political corruption peaked at tens of thousands and during one rally protesters stormed parliament. (Editing by Alison Williams)