Exit polls show that an anti-corruption party in India is on track to win a majority in state elections in the capital, a result that would see Prime Minister Narendra Modi facing his first state election defeat since sweeping to power last year.

The Aam Aadmi Party (AAP), or Common People's Party, is likely to win 38 seats in the 70-seat Delhi assembly, according to the average of four opinion polls released on Saturday after voting ended.

The official results will only be published on Tuesday.

A defeat for Modi's Bharatiya Janata Party (BJP) in the capital could harm his chances of consolidating power in parliament, where his reform agenda is being thwarted.

Less than a year after he resigned as Delhi's chief minister, Arvind Kejriwal, the head of the AAP, said: "People want a corruption free and bribery free Delhi and I'm hopeful they will vote accordingly." 

"I am confident the people will win and that the truth will win," he told reporters as he went to vote earlier in the day. 

'All talk, no action'

Modi needs to win most of the state elections over the next four years to gain control of both houses of parliament to deliver on his promise of jobs and economic growth.

The upper house, where his party is in a minority, is frustrating his efforts to pass laws related to tax and foreign investment.

"Modi has not done enough since coming to power. He is brilliant at marketing, but he is all talk, no action," said voter Gurjit Singh, 45, outside a polling booth in south Delhi, adding he had voted for Aam Aadmi.

The BJP is expected to win 29 seats and Congress, the party that has dominated Indian politics over the last century, but was trounced by Modi in last year's general election, will win three seats, its worse ever performance, the polls showed.

While polls have been badly wrong in the past, victory would be particularly sweet for former taxman Kejriwal, who was trounced by Modi when they both contested the parliamentary constituency of Varanasi in May's general election.

The BJP's campaign has been marked by infighting with party workers frustrated that Kiran Bedi, the first woman officer in the Indian Police Service, was appointed as the party's chief ministerial candidate, even though she only became a party member three weeks ago.

Earlier this week, the BJP ordered scores of its top national and state leaders to campaign for this weekend's high-profile election to the Delhi assembly.

Modi took out full-page advertisements on the front of several major newspapers in the capital on Friday in a last-minute effort to sway voters.

The BJP, which under Modi won India's biggest election mandate in three decades last May, has come first in three of four state elections over the past year.

It may also form a coalition government in the fourth regional assembly.

Source: Al Jazeera and agencies