Dr Kancha Ilaiah, a leading campaigner for Dalit rights in India, is visiting the UK this week.

Dr Ilaiah is Professor in Political Science at Osmania University in Hyderabad, India, and the author of a number of books on caste oppression in India. Of the practice of untouchability in India he has said: "Nowhere in human history has one group – the upper castes of India – been able to oppress so many for so long."

He recently testified at a widely-reported Congressional hearing in the USA, under the title 'The Abolition of Untouchability: the Key to Stability in India'. He described the roots and the ongoing reality of violence and discrimination against Dalits.

Dr Ilaiah is one of the key figures in the international movement for Dalit emancipation from caste oppression – often described as a 'hidden apartheid', due to the caste segregation throughout Indian society. The oppression of Dalits is wide-ranging, and well-documented. Dalits are compelled to perform the most menial and hazardous tasks, many Dalit women are sold into prostitution, and the use of Dalit child labour is widespread. Atrocities against Dalits are reported on an almost daily basis.

As hired workers, Dalits are typically paid under 50 percent of the minimum wage, and the careers of educated, more influential Dalits are hampered by their caste. Even during the 2004 tsunami relief effort, Dalits were segregated from upper-caste Hindus. Dalits are also excluded entirely from Hindu religious practices.

Notes to editors.

For 3,000 years, Indian society has been organised by its fourfold caste system. However, approximately 25% of India's population (over 250 million people) falls below the caste ladder, and these Dalits have faced centuries of oppression at the hands of the upper castes. Dalits perform the most menial and hazardous jobs in India, and many Dalit women are sold into prostitution. The literacy rate among Dalits is very low. Because they are considered by the Hindu religion to be a polluting influence, Dalit communities live in a considerable degree of segregation from the upper castes. Many restaurants, for example, keep separate drinking vessels for Dalit use, and Dalits often live downstream of the higher castes.

There also exists a legal discrimination against Dalits which in effect obstructs their freedom to adopt a religion of their choice, and thereby leave the Hindu religious system. In 1950, in an effort to address some of the injustices faced by the Dalit community, the Government of India introduced the Constitution (Scheduled Castes) Order, which bestowed so-called 'Scheduled Caste' status on Dalits, which creates certain privileges, including a quota system in employment and education. However, the 1950 Order contained the proviso that if Dalits should convert from Hinduism to another religion, they would lose their Scheduled Caste status, and the privileges that this entails. Although amendments were made in 1956 to include Sikhs and in 1990 to include Buddhists, Christian and Muslim Dalits are still denied equal rights even with other Dalits. Despite this disincentive to convert, the bulk of the Christian population in India is still drawn from among the Dalits. However, Dalit Christians are subjected on a widespread scale to social ostracism, and violence at the hands of Hindu extremists