Kuwait's constitutional court on Sunday nullified last year's legislative elections and ruled in favour of reinstating the previous parliament, state media said, as a political crisis roils the oil-rich Gulf state.

The September polls -- the most inclusive in a decade -- had seen opposition members clinch 28 out of 50 seats, giving them a parliamentary majority.

The vote marked a victory for opposition figures, many of whom had stayed out of elections in the past decade over what they saw as alleged meddling by the executive authorities over parliament.

"The Kuwaiti Constitutional Court issued a verdit on Sunday annulling the results of the 2022 National Assembly elections," due to discrepencies in the decree dissolving the previous parliament, the official KUNA news agency said.

It also ruled to reinstate the parliament that was elected in 2020 but dissolved following orders by the crown prince in June, KUNA said.

Lawyer Nawaf Al-Yassin said the ruling followed several electoral appeals.

"The appeals relate to the invalidity of the electoral process, the decrees calling for elections, and the decree dissolving the previous National Assembly," he told AFP.

Kuwait is the only Gulf Arab state with a fully elected parliament. One of the world's biggest oil exporters, it adopted a parliamentary system in 1962.

But repeated political crises have led to state paralysis and regular disputes with cabinet.

In January, Kuwait's government resigned only three months after it was sworn in due to disputes with lawmakers, the sixth government in just three years.