- Priyanka Gandhi Vadra has been made Congress in-charge of eastern UP
- Mamata Banerjee, Mayawati are also trying to unseat PM Modi
- Mayawati formed an alliance with Samajwadi Party in UP last month
Three powerful women politicians, each from a very different section of society, may pose a big threat to the chances of Prime Minister Narendra Modi winning a second term in the general elections due by May.
Priyanka Gandhi Vadra, part of the Nehru-Gandhi family that has ruled India for much of the time since Independence, joined the struggle in January, when the opposition Congress made her its face in eastern Uttar Pradesh.
Two other senior female politicians - the chief minister of West Bengal Mamata Banerjee, and Mayawati, former Uttar Pradesh chief minister - are also plotting to unseat PM Modi's ruling National Democratic Alliance (NDA) coalition by forming big opposition groupings, though there is no firm agreement between them as yet.
"The opposition has more powerful women leaders than the NDA, and therefore they will be able to carry conviction with voters generally, and with women voters, in particular," said Yashwant Sinha, 81, a former finance minister who quit the BJP, which dominates the NDA, last year.
"They should be very worried, especially after the defeat in the three major Hindi heartland states," he said, referring to BJP's losses in recent state elections.
The entry of Priyanka Gandhi into the political fray drew a gushing reaction from much of the media.
There were pictures of elated supporters dancing, a lot of talk of the 47-year-old's resemblance to her grandmother, former prime minister Indira Gandhi, and comments about her gifts as a speaker able to connect with voters. That contrasts with her brother, Congress leader Rahul Gandhi, who in the past has been criticised for lacking the common touch.
The other two women seen threatening PM Modi's grip on power have a lot more experience than Priyanka Gandhi, and both could be seen as potential prime ministerial candidates in a coalition government.
Mayawati, a 63-year-old former teacher who goes by just the one name, last month formed an alliance between her Bahujan Samaj Party (BSP) - which mainly represents Dalits - and its once bitter foes, the Samajwadi Party that tends to draw support from other lower castes and Muslims.
Then there is 64-year-old Ms Banerjee, who has twice been railways minister. Last month, Ms Banerjee - who built her Trinamool Congress party after leaving Congress in 1997 - organised an anti-BJP rally in Kolkata that attracted hundreds of thousands.
Party colleagues of the three women leaders said they were not available for comment.
PM Modi also cannot be accused of ignoring women's issues during his first term. He has launched a government campaign - Beti Bachao, Beti Padhao, or "Save the Daughter, Educate the Daughter" - and called for the eradication of female foeticide. His campaigns to provide toilets and subsidised gas cylinders for the poor are often promoted as ways to empower women.
He has six women in his 26-strong cabinet, though a lot of power is centralised with PM Modi and a couple of senior male lieutenants.
The BJP said it would seek votes on the basis of achievements under PM Modi and the opposition did not have a "positive alternative to the government, and its activities".
Congress has said it is open to forming a post-poll partnership with Mayawati's BSP and SP alliance, though it will be fighting against it in 78 seats. The alliance will not contest two Gandhi strongholds won multiple times by Rahul Gandhi and his mother Sonia Gandhi.
Mayawati told a press conference announcing the alliance with the SP that Congress was not part of it because they did not think "there would be much benefit in having them with us before the election".
The BSP, however, backs Congress-led governments in Madhya Pradesh and Rajasthan.
There is no formal alliance between Ms Banerjee and Congress, though she does know Rahul Gandhi and Priyanka Gandhi.
Dinesh Trivedi, a former union minister and a close aide to Ms Banerjee, said she enjoys a good personal relationship with Sonia Gandhi, a former Congress president, and so working with her two children would not be a problem.
"In terms of experience, Mamata Banerjee is far ahead," Mr Trivedi said. "I wouldn't be surprised if Rahul Gandhi or Priyanka Gandhi would look at Mamata Banerjee as somebody who could really inspire them."
The strength of Priyanka Gandhi, Mayawati and Mamata Banerjee as a potential opposition alliance is that they can appeal to different parts of the electorate.
Two Congress sources said the formal entry into politics of Priyanka Gandhi could help rejuvenate the party in Uttar Pradesh, where it is a marginal player. They said she could appeal to upper caste voters in the state who typically vote for BJP.
A Congress leader close to the Gandhis said she would attract women, young people, and floating voters.
Priyanka Gandhi is far from a political neophyte, having supported her brother and mother during previous election campaigns. She has also experienced political and personal tragedy, as Rahul Gandhi stressed in a speech last week.
"You have to understand my relationship with my sister - we have been through a hell of a lot together," he said.
"Everybody is like 'look, you come from this illustrious family, and everything is easy'. Actually it's not so easy. My father was assassinated, my grandmother was assassinated, huge political battles, wins in political battles, losses in political battles."
BSP spokesman Sudhindra Bhadoria said Mayawati's gender did not matter.
"She has managed a party from scratch to this level. The important fact is that she has organised large numbers, both men and women, Dalits, other backward castes, the poor, minorities," Mr Bhadoria said. "I don't fit them in the straightjacket of male-female. I think she's a national leader."
She is regarded as ambitious, according to a US diplomatic cable in 2008, among many thousands leaked by Wikileaks two years later.
But Mayawati has also been credited with empowering Dalits.
Ms Banerjee, who defeated a 34-year-old communist government in West Bengal in an election in 2011, is known for her streetwise political skills and portrays herself as a secular leader.