The former home secretary Jack Straw has admitted that dropping immigration restrictions on eastern European migrants was a "spectacular mistake" on Labour's part.

The Labour MP said handing immediate working rights to Poles and other nationalities who joined the EU in 2004 was a "well-intentioned policy we messed up". Writing in the Lancashire Telegraph, Straw said: "However careful you are, as a minister, in your analysis, many decisions are based upon predictions about the future, where, ultimately, your fate is in the lap of the gods. "One spectacular mistake in which I participated [not alone] was in lifting the transitional restrictions on the eastern European states like Poland and Hungary which joined the EU in mid-2004. "Other existing EU members, notably France and Germany, decided to stick to the general rule which prevented migrants from these new states from working until 2011. But we thought that it would be good for Britain if these folk could come and work here from 2004. "Thorough research by the Home Office suggested that the impact of this benevolence would in any event be 'relatively small, at between 5,000 and 13,000 immigrants per year up to 2010'. "Events proved these forecasts worthless. Net migration reached close to a quarter of a million at its peak in 2010. Lots of red faces, mine included." Straw, the MP for Blackburn, highlighted recent research indicating that the immigrants from that period were less likely to claim benefits than UK natives but added: "I have never underestimated the social dislocation that can occur when large numbers of people from abroad settle in a particular area – as has happened in east Lancashire. "But this latest research makes me feel a little better about this well-intentioned policy we messed up." The comments emerged after Straw's successor at the Home Office, David Blunkett, warned that an influx of Roma migrants into Britain could cause riots. Blunkett told the BBC that Roma groups from Slovakia who had settled in a district of Sheffield were behaving like they were living in a "downtrodden village or woodland". "We've got to be tough and robust in saying to people you are not in a downtrodden village or woodland, because many of them don't even live in areas where there are toilets or refuse collection facilities," he said. "You are not there any more, you are here – and you've got to adhere to our standards, and to our way of behaving, and if you do then you'll get a welcome and people will support you." Blunkett said: "We have got to change the behaviour and the culture of the incoming community, the Roma community, because there's going to be an explosion otherwise. We all know that."