India's Prime Minister faces biggest political setback since coming to power

India's Prime Minister and his right-wing BJP party are facing a major political setback after major swings against it in three key state elections.

Preliminary election results show India’s ruling Bharatiya Janata Party could lose power in three key states to the left-of-centre opposition Congress.

The outcome of this last round of state polls before general elections, to be held in the coming months, could potentially hand Prime Minister Narendra Modi his biggest political setback since coming to power in 2014.

The main opposition Congress party is leading in heartland states Rajasthan and Chhattisgarh, which were previously BJP strongholds.

However, after early results put Congress well ahead in the central state of Madhya Pradesh, the ruling BJP looks to be making a comeback.;

Analysts say a big loss for the BJP would signify dismay among rural workers and that Mr Modi is no longer invincible.

The Prime Minister has retained his popularity despite criticism he did not deliver on promises of jobs for young people and better conditions for farmers.

"We've all voted for Congress this time and our candidate is winning here," said Bishnu Prasad Jalodia, a wheat grower in Madhya Pradesh, where it appears as if Congress might have to woo smaller parties to keep out Modi's party.

"BJP ignored us farmers, they ignored those of us at the bottom of the pyramid."

The elections are also a test for Rahul Gandhi, president of the Congress, who is trying to forge a broad alliance with regional groups and face Modi with his most serious challenge yet, in the election that must be held by May.

In Rajasthan, the Congress was leading in 114 of the 199 seats contested, against 81 for the BJP, in the initial round of voting, India Today TV said.

In Chhattisgarh, the Congress was ahead in 59 of the 90 seats at stake, with the BJP at 24.

In Madhya Pradesh, the most important of the five states that held assembly elections over the past few weeks, Congress was ahead, with 112 of 230 seats.

The Hindu nationalist BJP was at 103, the network said.

Three other TV channels also said Congress was leading in the three states, with regional parties leading in two smaller states that also voted, Telangana in the south and Mizoram in the northeast.

Poll analysts cautioned that with the counting in preliminary stages, it was still too early to predict the outcome of state races involving millions of voters.

The rupee currency dropped as much as 1.5 percent to 72.465 per dollar, while bond yields rose 12 basis points to 7.71 percent after the resignation of Reserve Bank of India Governor Urjit Patel.