A Sri Lankan-born man who came to Britain 17 years ago is refusing to serve customers in his post office unless they speak English, media reported Thursday. Deva Sumarasiri, 40, whose shop is in a racially mixed inner-city area, believes he has to stand up for the English language because otherwise the social fabric of the country will disintegrate. Asians, eastern Europeans and others coming to his post office in Nottingham, central England, to claim state benefits or post letters must speak English or they will not be served, he said. “If you don't want to be British, go home,” he told the Daily Mail newspaper. “The fabric of the nation begins to unravel if we don't all speak the same language.” Sumarasiri, who flies British flags in his front garden, added: “An Asian woman came in here yesterday and I insisted she spoke to me in English. “She replied she preferred to speak in her mother tongue but I told her Britain was now her motherland and she should speak English.” Britain has for decades conducted an agonised debate about whether and to what extent immigrants should integrate into existing British society or keep their own cultural identity and traditions. Figures emerged earlier this week which indicated that one in seven children at state-run primary schools did not speak English as their first language. Prime Minister Gordon Brown's government is currently putting a bill through parliament which would require people to speak English if they want to earn British citizenship.