The village of Ikror is down a pitted track, three miles from the nearest town and surrounded by fields filled with wheat in winter and rice in the monsoon. Children climb trees in its dusty main square to shake down the hard green Indian plums.

There is little to distinguish it from the other 600,000 or so villages in India apart from the fact that it lies in Amethi, a district in the northern state of Uttar Pradesh that has been the bastion of India's foremost political dynasty for generations.

The fortunes of Ikror's 400 families – and most of their 1.2 billion compatriots – are deeply entwined with those of the descendants of Jawaharlal Nehru, the country's first prime minister and architect of modern India. As voting begins on Monday in India's general election – the world's biggest exercise in democracy – this is truer than ever. Since 2004, the member of parliament representing Ikror has been Rahul Gandhi – Nehru's great-grandson and the sole face of the venerable Congress party's campaign.

"The Gandhis, Congress – the same thing, two sides of the same coin," says Maqsud Ahmed, who at 75 is the oldest man in the village.

Since India gained its independence from Britain in 1947, when Ahmed was eight, the Congress party – and thus the Nehru-Gandhi dynasty – has dominated the country's politics. (There is no direct blood relation to Mahatma Gandhi, the independence leader.)

But pollsters predict that in this election, the Congress party, which has been in power since 2004, will record its heaviest defeat. No one foresees the immediate extinction of the Gandhis as a political force. But great changes are sweeping this country and one of the world's most successful political dynasties may well be a long-term victim.

From Delhi, the easiest way to reach Ikror is to fly to Lucknow, the state capital, on one of the private airlines that have thrived in India since a wave of economic reforms in the early 1990s dismantled a quasi-socialist, centrally planned state Though still cheap, India's famous trains have been hit by decades of poor management and underinvestment, and even the fastest express between the two cities takes more than six hours to cover just 500km.

Supporters show their support for Rahul Gandhi in Delhi. Photograph: Chandan Khanna/AFP/Getty Images

Uttar Pradesh (UP) has a population of 180 million and its socio-economic indicators are on a par with sub-Saharan Africa. Lucknow bears the scars of successive local rulers. There is the battered residency of the British and the hugely expensive monuments built by the former chief minister Mayawati Kumari. Its fabled old city, once the pride of the nawabs of Awadh, is slowly crumbling. But there is a gleaming new airport terminal and, as in every Indian metropolis, skeletal frames of apartment blocks destined for the new middle class rise in haphazard ranks on its ragged outskirts. Such properties, particularly in lawless UP, are often bought for cash, no questions asked.

"There is the law, and then there is UP. This is the wild west of India," says a local hotelier.

From Lucknow, the road to Amethi leads through a belt of new, private further education institutions, where the quality of the cement matches that of the teaching, and on into the countryside. This is the heartland of the northern plains, baking hot in summer, watered by the now-polluted Ganges and Yamuna rivers. It was the cradle of India's independence struggle.

Amethi and neighbouring constituency Rae Bareli have been represented almost without break by the Gandhi dynasty since Feroze Gandhi – husband of Indira, Nehru's daughter, who served four terms as prime minister – won a seat in Rae Bareli in 1951 during India's first democratic parliamentary election.

At Jagdishpur, a small industrial town just inside Amethi, a branch in the narrow road, choked until now with trucks, buses and tractors, takes you into the fields. There is no more traffic. The road forks repeatedly until, now a half-gravel country lane, it reaches Ikror.

This rural scene – with its fishermen, glossy black oxen and schoolchildren on bicycles – appears both unchanging and bucolic. In fact, it is neither. Life here, as across India, is tough and closely tied to global dynamics. Half the villagers are Muslim, and many families have at least one son working in the Gulf.

Cash sent home by the millions of workers overseas earned India $71bn last year and Ikror's relative prosperity is in part founded on these repatriated petro-dollars. The large and recently renovated mosque, almost as austere as its Gulf counterparts, silently testifies to how, as India's economy has faltered in recent years, the rupee has weakened significantly, boosting the value of remittances. With so few jobs created even in India's boom years, despite the 12 million or so new seekers each year, such employment is hugely important. "God has been kind to us," says Faradullah Khan, a farmer. "But why should our boys have to go to Dubai to find work?"

Making up 12%-14% of the total Indian population and long among the most marginalised, India's Muslims have been one of the most loyal constituencies of the Congress party.

No more, says Ahmadullah Khan. "We have been supporters of the [Gandhi] family for decades. But now we have to think twice."

Of the 200 non-Muslim families in Ikror, 150 are Hindu and from what are called "other backward castes", low down on the social hierarchy that still defines status in much of rural India, but higher than some. Many have land, if only small plots after generations of division among sons. They also have aspirations.

Vijay Maurya wants to set up a business, though he says he will have to find a job first to raise some capital. Many of his peers hope to move to India's cities: to Lucknow, which already has a population of 2.2 million, or Delhi, with 15 million inhabitants. But Maurya, 23, wants to stay at home. "I want to bring something the village doesn't have, to do some good," he says.

In recent years, there has been some improvement, albeit from a low base. Ikror has new paving and cement drains, courtesy of its representative in the state assembly. Electricity supply is marginally better, though now, in election season, when authorities direct power supplies to court voters in important constituencies, the village's televisions, pumps and fans stay on for the whole day. Only half the villagers now lack toilets at home, using the fields instead.

Lakshmi, a local social worker who rehabilitates juvenile offenders under a national scheme, says crime is too high, particularly among teenagers. There is a primary school in the village but the teacher, who she says is poorly trained and often absent, "doesn't teach anything".

These are perennial problems, and grievances, of rural India. Yet the response to them is no longer quite as fatalistic as it once was. At least half the villagers of Ikror are under 30 and have grown up bombarded by consumerist advertising and the slogans of a new, booming, shining India. In 1981, when Rajiv Gandhi, Rahul's father, first won this seat, only 33% of people in Uttar Pradesh were literate. Now 68% are. In the evening, the villagers watch the immensely popular soaps on entertainment and lifestyle channels such as Colors or the febrile news channels in which politicians – though not the Gandhis – are hectored and harassed by angry anchors.

The result is a wave of discontent directed at those who have represented them over the decades.

Sharat Pradhan, a veteran Lucknow-based reporter who has been covering politics in the region since Rajiv Gandhi's earliest campaigns in Amethi, said: "Nobody openly criticised 'the Family' like this before. There was some sign of this at the [2009] elections but not on this scale. This is completely new. There is this sense of empowerment. It's astonishing."

Such feelings are widespread. Across India, there is an accelerating breakdown in traditional deference towards those who have long assumed unthinking allegiance.

"There is no question that, as an India-wide phenomenon, there is a growing questioning of the vertical hierarchies of social relations that have resisted for decades," said Milan Vaishnav, a specialist on India's political economy at the Carnegie Endowment for International Peace.

Causing some consternation locally is the new Aam Aadmi (common man) party, which is challenging many of the fundamental principles of Indian politics. Its candidate, Kumar Vishwas, has spent weeks standing in dusty village squares, including Ikror's, giving speeches to a few dozen farmers.

"This is my personal battle against dynasty in politics. It should be about talent, not your father's name. Rahul Gandhi's ambition to be prime minister is an insult to the 64% of the population who are under 35 and who don't have a famous father," said Vishwas, a literary professor and poet.

Yet in surveys, nearly half of voters still express a preference for candidates who come from a political family or dynasty, and the most acute grievance of the people of Ikror is not Rahul Gandhi's assumption that he should be their representative, or the lack of local development, but that he is inaccessible – a complaint that would have been familiar to the Mughal emperors.

Indian farm workers in front of a billboard showing Bharatiya Janata party prime ministerial candidate Narendra Modi. Photograph: Rajesh Kumar Singh/AP

Nor do many in Amethi think the Hindu nationalist Bharatiya Janata party (BJP), led by the controversial Narendra Modi, will do more than dent Rahul Gandhi's massive majority. The BJP started campaigning late in Amethi, finally appointing a former TV star turned politician as its candidate. But even in the scruffy, scattered small towns around the district where support for the party appears strongest, most people will, despite their disappointment, vote for the Gandhis. In India, few see the point of casting a vote for losers. The goal for most communities in any electoral exercise is to be on the winning side and thus better placed to benefit from the winner's largesse. Modi's actions worry Muslims and the AAP is seen as untested.

"There is no campaign here as such," says Ashok Tiwari, who heads the Congress office in the small town of Gauriganj, a party stronghold not far from Ikror. "We simply need to ensure the voters reach the polling booths on election day. That's it."

Down a narrow path from the main village of Ikror is the basti (district) occupied by people from the Dalit caste. While the caste system is eroding in India's cities, it is alive and well in its villages. In these lanes, where there are no new drains, live those at the very bottom of the social pile. Thin children play with household utensils amid the flies. None attend the village school.

Like Muslims, the Dalits, who face daily systematic discrimination, have historically been the most steadfast supporters of Congress, even if in Uttar Pradesh many have switched their allegiance to a local party. The outgoing Congress-led coalition government launched huge subsidised work and food distribution programmes to help them achieve the escape velocity, as Rahul Gandhi called it, needed to break out of a cycle of poverty. But even here, few have much that is good to say about the man who represents them.

"If Rahul Gandhi says he is a friend of Dalits, tell him to come and see how we live. Politicians just make promises at election time and then vanish," said Kailash, who ekes a living for his family by selling fish caught in local streams.

His neighbour Kaushilya says her children eat two thin meals of vegetables, rice and lentils a day – when things are good. In most elections, she said, people "just vote the way everyone else does", though this time they "perhaps won't vote at all".

Her comments upset Vijay Maurya, the young aspiring businessman who lives 100 metres away in the main village. "It is important to vote, because that is how you have power," he says, earnestly. "We have faith in democracy."