Kuwait's Muslim Brotherhood-linked Islamic Constitutional Movement [ICM] has said it will end its boycott of general elections in the Gulf state.
The Islamist group is among a broad alliance of Islamist, nationalists and liberal opposition groups which have refused to take part in elections in 2012 and 2013, after changes to the electoral law.
At the time, the opposition alliance said the new changes - endorsed by Kuwait's top court - would allow the government to control parliament.
Now, after four years, the Islamist alliance has had a change of heart.
It said the opposition's absence from parliament had "contributed to an increase in corruption, a setback in development...and the passing of several laws that breached the constitution".
The move comes after former opposition MP Ahmed al-Khateeb urged the alliance to participate in the upcoming elections as their absence had left parliament in "corrupt hands".
Other Islamist movements - including more extreme Salafi groups - also voiced their concern about the gradual loss of "Islamic principles" in the Gulf state.
The alliance feels it has been detached from society since boycotting the elections, a source in the alliance told The New Arab.
He said there has become generational split in society and that the Islamist group has been forced to re-enter political life to help Kuwait return to its religious traditions.
The alliance will now field candidates for polls in 2017, he said.
Earlier this month, a smaller Islamist group, the Principles of the Nation, also ended its boycott.
The opposition held massive street protests in 2011 and 2012 demanding democratic reforms and an elected government.
But over the past two years, the strength of the opposition alliance - which last controlled parliament in 2012 - weakened considerably as the groups became fragmented.
OPEC member Kuwait was rocked by political disputes between 2006 and 2012, during which a dozen governments were formed and parliament was dissolved six times.
But the oil-rich emirate - which has amassed over $600 billion in assets - has seen relative calm since July 2013 parliamentary polls, although low oil prices threaten this.
Although Kuwait has the Gulf's most vibrant elected parliament, a majority of key government posts are still held by members of the ruling al-Sabah family, which has been in power for the past 250 years.
Agencies contributed to this report.