NEW DELHI (Reuters) - India's upper house of parliament on Monday approved a $20 billion scheme to distribute subsidized wheat and rice to 800 million people, backing an anti-malnutrition drive that investors fear will mean missing the fiscal deficit target.

The Food Security Bill is seen as a vote winner by the ruling Congress party as it prepares for elections due by May next year. But investors reacted negatively to the plan when the lower house approved it last week, on worries the government will struggle to contain the cost of subsidies.

The scheme has now been passed by both houses. Before becoming law it must be signed by the president, a formality.

(Reporting by Mayank Bhardwaj; Editing by Frank Jack Daniel)