Jobs: One of the pressing issues during Modi's five-year tenure was lackluster job creation, despite strong economic growth. The Centre for Monitoring Indian Economy think tank estimated that around 11 million jobs were likely lost in 2018.
In a survey of more than 273,000 people, the election watchdog Association for Democratic Reforms found that better employment opportunities was the top priority for voters.
Both the BJP and Congress, in their respective election manifestos, promised to create new job opportunities in the country.
Security: In February, tensions between India and Pakistan escalated after military planes from both sides carried out tit-for-tat air strikes in each other's territories, and their troops traded fire along the de facto border in Kashmir. Analysts have said the skirmish boosted support for Modi and the BJP as security concerns overtook economic worries.
"Dismal showing at the state elections last year left little doubt that the BJP had lost significant grip on government," Vishnu Varathan, head of economics and strategy at Mizuho Bank, wrote in a note. "Since India-Pakistan tensions flared in February this year, support for the BJP (NDA) has rebounded."
"This has handed the BJP the gift of nationalist and national security planks on which the BJP is able to boost support standings," he added.
In its election manifesto, the BJP said it would strip special rights and privileges from permanent residents in India's Muslim-majority state, Jammu and Kashmir, which could potentially invite a backlash.
Farmers: India's farmers, who make up a sizable portion of the workforce, have struggled for years due to low crop prices, rising costs, demonetization and widespread drought.
Both parties have outlined potential policies designed to boost wages for farmers.
BJP, for its part, says it plans to launch a pension scheme for small and marginal farmers to provide them with social security in old age. Modi has also pledged to spend 25 trillion rupees (around $359 billion) in farm and rural productivity. In the February budget, the BJP announced that farmers who own up to 5 acres of land will receive 6,000 rupees in income support each year. That policy will be extended to all farmers, according to the party's election manifesto.
In a political blow to Modi, the BJP lost elections in three important rural states last year.
Congress has also outlined a number of schemes to help farmers including expanding an existing jobs program to guarantee 150 days of employment in a year and to write off farm loans. The party also has an ambitious pitch to alleviate poverty in India by handing out about $1,000 per year to the bottom 20 percent of households. The plan has drawn skepticism from economists who questioned how the program will be funded and who would be eligible for it.
— Reuters contributed to this report.