Lok Sabha polls will be held in seven phases beginning from April 19 and the counting of votes will take place on June 4 for the world's biggest election exercise in which Prime Minister Narendra Modi will bid for a third consecutive term.

The other phases will be on April 26, May 7, May 13, May 20, May 25 and June 1, Chief Election Commissioner (CEC) Rajiv Kumar said at a press conference on Saturday.

Assembly elections in Arunachal Pradesh and Sikkim will be held on April 19, and in Andhra Pradesh on May 13. Elections to Odisha assembly will be held in four phases on May 13, May 20, May 25 and June 1.

Bypolls will also be held for 26 assembly constituencies, Kumar said at a press conference flanked by two new Election Commissioners Gyanesh Kumar and Sukhbir Singh Sandhu.

Polling will be held in all seven phases in three states - Bihar, West Bengal and Uttar Pradesh.

In the first phase on April 19, voting will take place in 102 constituencies spread over 21 states/UTs, with 10 states/UTs completing the poll process in this phase.

Voting will take place in 89 constituencies across 13 states/UTs in the second phase on April 26, Kumar said, adding that the poll process would be completed in four more states/UTs.

In the third phase on May 7, voting will take place in 94 constituencies spread across 12 states/UTs. With this, polling will be completed in six more states/UTs.

In the fourth phase on May 13, 96 constituencies spread across 10 states UTs would vote. With this, three more states/UTs would have completed voting.

As many as 49 constituencies spread across eight states/UTs will vote in phase five on May 20. This phase will see voting completed in three more states/UTs.

In the sixth phase on May 25, voting will take place in 57 constituencies spread across seven states/UTs. Polling in two more states/UTs would be completed with this phase.

The seventh and final phase will take place on June 1 in 57 constituencies spread across eight states/UTs. The polling process in eight states/UTs would be completed.

Led by Prime Minister Modi, a buoyed BJP, which swept the November assembly elections in Rajasthan, Madhya Pradesh and Chhattisgarh, will take on the opposition parties which have been trying to put up a joint front under the umbrella of the INDIA bloc, with limited success confined to some states.

The CEC said the poll authority is prepared to counter the challenges of four ‘M's – muscle power, money power, misinformation and Model Code of Conduct violations.

"I would appeal to parties to maintain decorum during the campaign and refrain from personal attacks," Kumar said.

The CEC said children should not be used in campaigning and the poll watchdog will be very strict on that account. He also said advertisements masquerading as news will not be allowed.