Incidents of recorded race crime in Britain have soared by up to 300 per cent over the past four years, leading to concerns that efforts to calm tensions within communities are failing.

Overall, there was a 39 per cent increase in the number of racially aggravated offences reported to police in England and Wales between 2003 and 2007, according to official figures obtained from the Home Office by the Conservatives. The number of such offences - which include wounding, harassment, assault without injury and criminal damage - recorded by police rose from 31,436 in 2003 to 43,780 in 2007.

But the national increase masks more dramatic rises in race crime in many parts of the country. Virtually all police forces, with the exception of the Metropolitan Police, recorded sizeable increases in racially motivated incidents. In South Yorkshire the number of racially aggravated offences reported to police rose by 330 per cent, from 242 incidents in 2003 to 1,037 in 2007. In Merseyside there was a 94 per cent increase in racially aggravated offences, from 734 to 1,423, and in Greater Manchester there was a 56 per cent rise from 2,353 incidents to 3,677 incidents. In Hampshire there was a 320 per cent rise from 317 offences to 1,326.

Suresh Grover, chief executive of the Monitoring Group, the anti-racist civil rights group that has advised the family of the murdered black teenager Stephen Lawrence, said much of the increase could be attributed to attacks on new types of migrant who have arrived in Britain, and a greater willingness by police to record racist incidents. 'In areas like Southampton, student bodies are becoming more aware of the need to report attacks. Bodies representing students from Eastern Europe and China are reporting many attacks,' said Grover. In recent months the Monitoring Group has received reports of attacks on Portuguese, Lithuanian and German workers, suggesting that there is increasing resentment towards economic migrants.

Grover said part of the rise was also down to the rise of the extreme right. He added that the displacement of asylum seekers across the UK had seen them become increasingly vulnerable to attacks.

Curbing racially aggravated crime is a key government target, as outlined in its 2005 Community Cohesion Strategy. The Conservatives said it was clear from the figures that more work had to be done before that goal was achieved.

'A 40 per cent increase in racist crime in just four years demonstrates 10 years of government failure on community cohesion,' said David Ruffley , the Tory spokesman on police reform. 'These crime figures show the government's failure to improve community cohesion and crack down on racism.'

A recent government citizenship survey showed an increase in perceptions of levels of racism in Britain. Of those surveyed, 56 per cent said they believe there is more racial prejudice in Britain now than five years ago. And last year the Commission for Racial Equality warned that 'segregation - residentially, socially and in the workplace - is growing, and that extremism, both political and religious, is on the rise as people become increasingly disillusioned and disconnected from each other'.

A Home Office spokesman said the figures showed that victims of race crime were increasingly confident that the police would treat their cases seriously. He added that the government wanted to 'encourage the reporting of such crimes so they can be properly investigated and we can bring more offenders to justice'.