The surge in new National Insurance numbers in Newham has prompted concerns over pledges to provide thousands of skilled construction jobs to the local community.
About 2,700 workers are on the Olympics site, rising to 9,000 by 2010. Estimates of the number of migrant workers there - mostly from Poland and Baltic states within the European Union - range from 10 to 70 per cent.
Labour MP Frank Field, who published the National Insurance figures, said: 'It is totally lawful but British taxpayers and lottery players are paying for jobs for foreign workers and it is not what we signed up for."'
The ODA has promised a skills legacy for east London and is in the forefront of the Government's agenda under which Gordon Brown promised 'British jobs for British workers'.
The ODA has a plant training school at the Olympic Park and says one in 10 of its workforce was previously unemployed. But the ODA is also under pressure to balance its books after losing £500million in private sector investment in a year with the credit crunch and, according to unions, has targeted savings on labour costs.
Construction workers' union Ucatt is increasing pressure on the ODA to continue to honour agreed minimum site rates. It is thought that migrant workers hired through agencies are typically paid up to £2 less per hour than their British counterparts.