'The world of Indian street food -- a great social leveller -- is a parallel culinary universe that sustains millions of foreign tourists who backpack across the country every year and the three million-strong Indian middle class looking for a change of palate outside their kitchens.

'For legions of poor people in the country working outdoors, street food is a lifeline,' said Arvind Singh, coordinator of the National Street Vendors Association of India.

'We could survive on street food all our lives after the kind of food we are served in our hostel. Where else can you get a tasty meal for Rs.100?' asked Delhi University student Prashant. He was splitting with friend Mridul a platter of piping hot litti chokha from Bihar.

'Cooking fresh food is always healthy,' said Sujata Sahu from Bhubaneswar, who has been vending mini lunch platters of fish curry, dalma and rice in the heart of the Orissa capital for 15 years.

'Dalma is a traditional dal served in the temple of Puri. It is a complete meal made of arhar dal, five different vegetables and 11 spices,' explained Sujata's husband.

Frequent crackdowns by municipal authorities have hit his trade, complained vendor Ayodhya Prasad Pradhan, who sells five kinds of stuffed paranthas in the capital's South Ganesh Nagar.

The Supreme Court said in a recent judgement that street food must be prepared and sold in a hygienic manner. 'But local municipal corporations, especially in Delhi, have interpreted the order as banning the sale of street food,' Singh said. 'This is posing a threat to the survival of the vendors.'