More than 20,000 traders, farmers and shopkeepers protested on Wednesday against the entry of private retail giants like Wal-Mart into India which they say would destroy millions of livelihoods.
The protests in Mumbai were the biggest yet against the ambitions of foreign and local companies to introduce Western-style supermarkets into a fragmented $350 billion market expected to double in size by 2015.
The protests reflect wider social tensions in the fast-growing Asian giant, where private investment is frequently opposed by traders scared of new retail competition and villagers worried their land will be taken for multinational factories.
Farmers wearing traditional long white shirts and white caps marched in long processions waving posters with slogans like "It's now or never. Wal-Mart quit India."
"This is a do or die battle for us. Either they go or the small traders and farmers perish," said Dharmendra Kumar, Director of India FDI Watch, spearheading the campaign against private retail in India.
Past demonstrations had failed to attract large numbers but retail opponents have managed to force Reliance Industries, India's biggest listed company, to lay off 1,000 staff and close stores after protests in north and east India.
Reliance Retail, a subsidiary of Reliance Industries, plans to invest more than $5.5 billion in its venture.
Protesters also fear US giant Wal-Mart Stores is trying to enter Indian retail by the back door after it signed a wholesale venture with India's Bharti Enterprises. Currently foreign multibrand retail stores are not allowed in India.
Foreign retail giants Carrefour and Tesco have also shelved investment plans due to the uncertainty.
Large companies still account for only three percent of India's retail market.
Protests have focused on Reliance partly because its size and brand name in India make it an easy target. Some other local retailers, such as Spencer's, operate dozens of stores in India without facing so many protests.
Retailers fear protests could snowball in India as politicians feel it could win them votes, especially with talk of a snap general election next year.
"Earlier, there were protests from only a few organisations, but now some states are proposing to ban modern retail, and that is a very serious issue," said Gibson Vedamani, head of Retailers Association of India, which represents 200 local and foreign firms.
Those against private retail say 40 million jobs will be lost, against the 2 million that modern retail promises to create.
"They have government support, financial muscle. It is like they are boxing with gloves and we are being asked to fight bare-handed without any protection," said Sharadkumar Maru, head of a grain merchants' association.
(Additional reporting by Rina Chandran in Mumbai)