Israelis are voting in the fourth general election in two years in what is widely seen as a referendum on the prime minister, Benjamin Netanyahu.
The previous three elections – a record cycle – ended inconclusively. A unity government, which formed to break the impasse, collapsed in December.
Polls ahead of the latest elections point towards another stalemate.
They are being held as Israel emerges from lockdown and two weeks before Mr Netanyahu’s corruption trial resumes.
The prime minister is fighting charges of bribery, fraud and breach of trust. He denies the accusations against him, which he says are politically motivated.
Since the last elections in March 2020, Israel has gone through three lockdowns to try to curb the spread of coronavirus.
Mr Netanyahu’s opponents have accused him of mishandling the crisis, but the economy has largely reopened in recent weeks, infection rates have plummeted and the prime minister has touted Israel’s rapid inoculation programme as a major achievement.
At its peak, Israel was one of the worst-hit countries in the world, but more than half the population has now received at least one vaccination dose.
Aside from the pandemic crisis, opposition parties have focused on Mr Netanyahu’s political dominance as the country’s longest-serving leader, arguing that the country is overdue a change.
The prime minister has been in power continuously since 2009, having served an earlier three-year term in the late 1990s.
His right-wing Likud party is expected to win most seats but fall far short of the 61 needed to be able to form a government without the support of other parties. Israel’s electoral system has resulted in coalitions or, more rarely, unity governments since the state was founded in 1948.
However, polls suggest that even a bloc of right-wing parties willing to back the prime minister could struggle to pass the numerical threshold to enable him to stay in office.
Anti-Netanyahu parties are expected to outperform the pro-Netanyahu bloc but analysts say the extent of political differences between them mean that even if they win 61 or more seats, they are unlikely to be able to put a government together.
If no bloc can achieve a workable majority, a fifth round of elections could be called.
Israel has been blighted by political paralysis since the April 2019 election, when Likud won the most votes but failed to form a governing coalition. Although the party stands strongly behind Mr Netanyahu, mass demonstrations against him have been held weekly outside his Jerusalem residence, apart from during periods of tight lockdown.
Tens of thousands of opponents took part in the latest such rally on Saturday night, in one of the biggest gatherings of its kind since the demonstrations began.