Indian Prime Minister Narendra Modi's party lost a third of its rural parliamentary constituencies in last month's election, a voter analysis shows, reflecting discontent in the countryside over lack of jobs and high inflation.

The Bharatiya Janata Party's poor showing in the vast heartland cost the ruling party its majority in parliament, forcing Modi to depend on regional allies to muster the simple majority required to govern the world's most populous country.

The BJP, which held 201 rural constituencies in the 543-member parliament, retained only 126 of them in the mammoth election, the analysis showed.

The seats do not include those in the regions of Assam, Jammu and Kashmir and Ladakh, as a reorientation of constituencies there meant there is no direct comparison with data from the prior election.

Rahul Verma, a political expert at the New Delhi-based Centre For Policy Research, said Modi's party especially lost ground in the big heartland states of Uttar Pradesh and Rajasthan, which have trailed more prosperous southern and western parts of India in the pace of economic development.

"The rural distress would have played a factor," he said. Under Modi, India has become one of the world's fastest-growing economies, but there are too few jobs for the millions entering the workforce each year and growth has been uneven.

Families in rural India, home to 60% of its 1.4 billion people, have seen incomes halve as they also struggle to keep up with rising costs and fewer jobs.

Modi campaigned on his track record of rapid growth, government programmes to help the poor and muscular Hindu nationalism aimed at the party's conservative base.

But the results showed the BJP ceding ground in the country's 344 rural or semi-rural seats to the opposition that targeted employment, inflation and income disparity as core issues.

"Perhaps BJP was confident before the elections, that's why it did not make any major announcements for the rural parts in its interim budget, and that could have played a role," Verma added.

The Unemployment rate rose to 8.1% in April from 7.4% in March, private think-tank Centre for Monitoring Indian Economy has said. The figure was at 6% before the COVID-19 pandemic.

The BJP has acknowledged employment was a factor in the election and said "whatever best can be done is being done".

Its vote share in the 126 seats the BJP managed to retain dropped about three percentage points. Modi's average margin of victory in those seats fell to 15.6% in this election from 22.9% in 2019.

Meanwhile in 179 urban seats, the BJP managed to hold on to 78 of the 90 it had won in the last election.

Voters were worried about inflation, unemployment, decreasing income and the government's handling of corruption and fraud, according to the Lokniti-CSDS post-election survey published by the Hindu newspaper. (Reporting by Chris Thomas, Krishn Kaushik and Anand Katakam; Editing by Alex Richardson)