But the party finds itself at a crossroads, and celebrations following last month's 30th anniversary of its rule have been tempered by what one insider described as 'cathartic introspection'.

Broadly speaking, Indian communists are social democrats operating within the parameters of the multi-party democratic system.

'On paper, the CPI(M)'s goal seems to be to provide good, responsible governance to the have-nots,' says Partha Chatterjee, of Calcutta's Centre for Studies in Social Science.

'But they face plenty of obstacles because of the constitutional framework.'

West Bengal's principle opposition party, Trinamool Congress, has called the CPI(M)'s 30-year rule over the state's 80 million people a 'nightmare of suppression and repression'.

Cadres waving red flags and singing revolutionary songs marched to a stadium in the state capital, Calcutta, last month to mark the anniversary of CPI(M)'s rule and hear West Bengal's chief minister, Buddhadev Bhattacharya, and other Marxist heavyweights tout their economic and political achievements.

Among the speakers was Jyoti Basu, the charismatic 93-year-old former chief minister, who had served from 1977 to 2000 before passing the baton to his protege, Mr Bhattacharya. Mr Basu enjoys the distinction of being India's longest-serving chief minister - a record unlikely to ever be broken.

Clouding the anniversary, however, is an uprising among peasants, ironically empowered by communists in the initial stages of their rule, against the acquisition of farmland for new factories. The increasingly violent agitation against forcible acquisition of paddy fields has killed 25 people this year, including 14 who were shot dead by police in Nandigram. The violence has virtually paralysed the much-hyped industrialisation campaign in the Marxist bastion.

Ultra-leftist Maoist rebels pose another major challenge. Maoist guerrillas are on the rampage in three of West Bengal's poorest districts, where scores of CPI(M) leaders accused of post-colonial imperialism and feudalism have been gunned down in recent years.

Still, the state's ruling coalition romped to a seventh term last year, while promising to industrialise the predominantly agricultural state to generate jobs.

But the deaths of the farmers in Nandigram in March shattered the government's pro-poor image. Many left-leaning intellectuals, including poets, painters and film personalities, vehemently criticised the CPI(M)'s plans to create Chinese-style special economic zones, and cut their ties to the party after the carnage in Nandigram.

Mr Bhattacharya's attempts to woo them back have failed miserably, revealing the magnitude of public anger over the issue.

Analysts say the CPI(M) will face a real test in next year's panchayat, or elections for village development council. Some observers believe the peasantry, the party's traditional base, will have deserted it by then.

The principle factor behind CPI(M)'s spectacular success over the years was the land-reform programme it began in 1980. It established the rights of landless labourers and farmers over the land they tilled, turning West Bengal's rural population into avid supporters.

The policy won lasting support as the proportion of people living below the poverty line dropped from 52 per cent to 14.8 per cent, well below the national average of 25.7 per cent.

Increased rural income reduced the pressure on the cities, making political management of urban problems easier.

Bengal witnessed a 210 per cent increase in literacy and a 50 per cent drop in infant mortality. Party membership, meanwhile, climbed to 274,000 from 22,000 in 1977. And levies collected from members have risen from 5 million rupees (HK$960,000) 30 years ago to 75 million rupees today.