India's rich and famous vote in country's mammoth election

Billionaires and Bollywood stars urged Indians to go out and vote as they took their turn with Mumbai's millions of slum dwellers Monday to cast ballots in the world's biggest election.

India's film and finance capital took centre stage in the fourth of seven rounds of the mammoth democratic exercise due to wrap up on May 19 with results expected four days later.

At least 40,000 police and security personnel were deployed across the megacity of 20 million people while workers were given a holiday to vote for Mumbai's six lawmakers. Twenty-six of the 10,000 polling stations were staffed by women only.Media scrums were set up at the stations where India's richest man, Mukesh Ambani, Bollywood superstars including Amitabh Bachchan and Aamir Khan, as well as Indian cricket legend Sachin Tendulkar voted.

“It's a very proud and happy day for all of us today. Happy voting day everyone,” Bollywood superstar Aamir Khan said alongside his director wife Kiran Rao at a school in the plush Bandra area.

“This is the moment that matters.... Every vote is a voice that counts,” tweeted Priyanka Chopra, alongside a selfie of herself showing indelible ink on her finger nail.

Prime Minister Narendra Modi's Bharatiya Janata Party (BJP) and their partners Shiv Sena, a Hindu chauvinist party, together won all of Mumbai's seats at the last elections in 2014.

They also won all but a handful of seats in Maharashtra state, of which Mumbai is the capital.

Now former MP Priya Dutt, a member of one of India's most famous acting families, is trying to make a comeback for the opposition Congress party in the city. Actress Urmila Matondkar is also running for Congress.

Tycoon backs Congress candidate

The concerns of the rich and famous — Ambani and his family live in 27-storey luxury high-rise — were far from the ordinary voters in line however.

“The most pressing issue for Mumbaikars is unemployment and rising costs of living,” shop trader Jignesh Shah told AFP as he queued in the suburb of Chembur.

“As a middle class family it gets really difficult when real estate costs are so high and transportation is a mess,” the 56-year-old added.

About 60 per cent of Mumbai's population live in slums.

At the other end of the wealth spectrum, Ambani has raised eyebrows by backing the opposition Congress candidate in his Mumbai constituency, although the BJP is not standing in that seat.

Ambani has regularly spoken in support of Modi's BJP government and the Reliance Industries tycoon's son, Anant Ambani, attended a recent Modi rally.

Monday's voting in nine states will be particularly crucial for Modi's chances of securing a second term after his landslide win in 2014.

More than three dozen seats were at stake in Madhya Pradesh, Uttar Pradesh and Rajasthan states, all traditional BJP Hindu strongholds.

Defeats suffered by the ruling party in three recent state elections have raised Congress hopes that it can eat into the government's majority.

Modi's party won 282 of the 543 seats contested last time but analysts say this election will be closer.

Congress has hit out at Modi's handling of the economy, the failure to produce promised jobs and massive debt in rural India which has seen thousands of farmers commit suicide.