Opposition MPs in Kuwait have accused the government of being behind a police crackdown on a rally that left at least five people injured.
About 20 MPs have vowed to question the prime minister, a member of Kuwait's royal family, in parliament on Sunday.
Opposition supporters were protesting against an alleged "government plot" to amend the constitution in a bid to suppress freedom and democratic rights.
The government says the public gathering was not authorised.
Kuwait was the first Arab state in the Gulf to usher in parliamentary democracy.
Opposition leaders say members of Kuwait's special forces used batons to push back participants at an opposition rally west of Kuwait City on Wednesday.
"This was an outrage unprecedented in Kuwait's political history. There was a deliberate will to beat the opposition physically," MP Jamaan al-Harbash told al-Jazeera television.
"We have decided to quiz the prime minister [Sheikh Nasser Mohammad al-Ahmad al-Sabah] and the motion will be filed on Sunday," he said.
Witnesses said that at least five people were injured, while the local media put the number at 14, including four lawmakers.
Sheikh Nasser, a nephew of the emir, has been under constant political pressure ever since he became prime minister in February 2006.
Since then, the cabinet has resigned five times and the ruler has dissolved parliament three times.
Oil-rich Kuwait has a 50-member parliament. Of the 16 cabinet ministers, 15 are unelected, but have similar voting rights as elected MPs.