India's premier urged lawmakers Thursday to engage in "responsible" debate as the government seeks to push the annual budget and controversial economic reforms to spur the economy through parliament.

Prime Minister Manmohan Singh's appeal came as parliament was to begin a new session in which the government is due to announce next week a budget expected to feature the most belt-tightening in years despite elections looming in 2014.

Past parliamentary sessions have been stormy with lawmakers accusing the left-leaning Congress government of corruption, resulting in the passage of little legislation.

"The way we conduct financial business before parliament will be a crucial test of how we deal with the formidable challenges we face," he said, referring to an economy growing at a decade low and sharply deteriorating public finances.

"It is now a challenge for all of us to take credible action to ensure we are least affected by global slowdown," Singh told reporters as the parliamentary session was about to begin.

"We look forward to responsible dialogue," he said.

India, the world's most populous democracy, is struggling to avert a ratings downgrade of its sovereign debt to junk status due to its worsening finances and growth expected to be as low as 5.0 percent in the fiscal year to March 2013.

Expansion is far below the near double-digit levels Asia's third-largest economy posted before the onset of the global financial crisis.

Other key bills slated for the session include measures to hike foreign investment in insurance, open the pension sector to overseas investors and supply subsidised grain to India's hundreds of millions of poor.

The session was due to kick off with a speech outlining the government's legislative programme by recently elected president Pranab Mukherjee.

Singh's minority government anticipates its reform agenda could be hijacked by opposition anger over new bribery allegations involving the $748-million purchase of 12 helicopters from AgustaWestland.

The Anglo-Italian company is a unit of Italian defence giant Finmeccanica, whose chief executive Giuseppe Orsi was arrested last week in Milan. The Italian company has denied any wrongdoing.

But a measure to toughen anti-rape laws following the brutal gang-rape and murder of a 23-year-old medical student in December is expected to win quick approval from lawmakers in light of widespread public anger.