NEW DELHI (Reuters) - As Prime Minister Narendra Modi faces voter fatigue and some resistance from a resurgent opposition in India's mammoth general election, foot soldiers of his party's Hindu nationalist parent have stepped in to help regain momentum, insiders said.

With less than two weeks left of a six-week voting schedule, voter turnout has been lower than previous elections, raising concern within the Bharatiya Janata Party (BJP) that some of its core supporters were staying away.

Modi's party, chasing a rare third term in office, has also faced stronger opposition than anticipated in a handful of states, leading election experts and Indian financial markets to adjust forecasts of a landslide win.

With no exit polls allowed until all the voting is completed on June 1, it's difficult to judge how well or poorly candidates are faring. But most analysts say Modi should be able to retain a majority in the 543-seat parliament when votes are counted on June 4.

"The trend is suggesting that Modi will be back in power with a reduced majority," said Rasheed Kidwai, a visiting fellow at the Observer Research Foundation think tank.

But he added: "Any shortfall of a clear mandate of 300 seats for BJP will reflect poorly on Modi."

At the start of the campaign, Modi was projected to win up to three-fourths of the seats, with the opposition led by Rahul Gandhi, the scion of the Gandhi-Nehru dynasty, a distant second.

After the first two phases of voting, though, analysts and political workers said the chances of the BJP getting above 362 seats, the two-thirds majority required to bring changes in the constitution, had been affected.

One reason the opposition is clawing back ground is the fading of the euphoria in India's Hindu majority when Modi inaugurated a temple in January on a site disputed with the country's minority Muslims.

Bread and butter issues seem to be replacing religious fervour in many parts of the country.

Jobless youth in northern Haryana state have held street protests against the BJP during the campaign and in western Maharashtra, farmers incensed over a ban on onion exports canvassed support for an opposition candidate.

In the big, battleground state of Bihar, a BJP lawmaker has defected to the opposition Congress party saying the poor have been left behind in India's world-beating economic growth.

Some of the unhappiness is resulting in a swing to the opposition or in apathy, analysts have said.

"The decline in voting has been a cause of concern in recent weeks and we have been working to bring a shift in the numbers," said Rajiv Tuli, an official at the Rashtriya Swayamsevak Sangh (RSS), the Hindu group that is the ideological parent of the BJP.

"Meetings, outreach campaigns and even a renewed push to remind voters about ensuring a full-majority government comes to power did become critical after the first phase of voting."

GO OUT AND VOTE

RSS volunteers are hosting neighbourhood meetings in their homes to persuade people to go out and vote, said Ritesh Agarwal, the senior publicity official for the group in the New Delhi region.

Three national spokespersons of the BJP said they were aware that the RSS was working to help improve voter turnout but declined comment on how this would affect the BJP.

"I don't think there is any sense that BJP is in a weak position," said spokesperson Shehzad Poonawalla, adding that a low turnout affected all parties and that voter numbers had increased after the first two phases.

In Haryana, some youngsters have criticised a government decision to cut back on recruitment to the military and switch to temporary commissions to control a bloated defence budget. Jobs are so scarce, residents say, that people are lining up for employment in Israel which has turned to India to plug a labour shortage following the war in Gaza.

"We see no future for ourselves," said 28-year old Kuldeep Singh in the northern state's Jahangirpur village, where black ink was smeared on walls displaying Modi's campaign slogans.

Ganesh Wadhwan, a farmer in Maharashtra's Dindori constituency said he sought funds for opposition candidate Bhaskar Bhagare ahead of the vote there on Monday to punish the Modi government for blocking onion exports.

"We believed Modi would double our income as promised. But instead, our incomes have halved," said Wadhwan.

Some analysts say there is also considerable disapproval of the government in Bihar, one of India's poorest states which has fallen behind as incomes climb in other parts of the country.

Together, Maharashtra, Bihar and Haryana account for nearly 100 seats in parliament, but it was not clear how far the discontent had spread there or in other parts of the country.

The opposition has said its campaign rallies are drawing good crowds and Gandhi, the alliance leader, is predicting it will unseat the BJP and form the government.

India's stock markets fell sharply last Monday on the possibility of political instability before recovering later in the week.

The underground betting market is currently predicting that the BJP will win fewer than 300 seats but well clear of the 272 required for a majority, according to a trader who runs one of the betting pools.

He declined to be identified as these pools are illegal.

Yashwant Deshmukh, founder of polling agency CVoter Foundation, said all the evidence pointed to Modi winning.

"Jobs and unemployment are huge issues but not really an electoral issue. When we asked who will give a solution to these problems - jobs, inflation, unemployment and the economic situation - Modi's score was 2:1 over Rahul Gandhi."

(Reporting by Manoj Kumar in ROHTAK, Rupam Jain, Rajendra Jadhav, Shivangi Acharya and Nimesh Vora; Editing by Raju Gopalakrishnan)

By Rupam Jain and Rajendra Jadhav