New figures out today reveal that, on the Government's own figures, the benefit to each member of the native population of the UK from immigration is worth about 4p a week - or less than the equivalent of a small Mars bar a month.

In an analysis of a series of reports on the economic impact of immigration on the UK think-tank Migrationwatch has found that overall the much vaunted contribution of immigrants to the economy is very slight indeed - a finding that coincides with the results of major studies around the world.

'The Government seek to present the record immigration levels as being nothing but good news for the host community as a means of deflecting attention from some of the many problems it is causing and to neutralise the deep public disquiet they know is out there,' said Sir Andrew Green, chairman of Migrationwatch. 'Of course many immigrants make a useful contribution to the economy but taken in total the economic benefit is at best marginal.

'The main beneficiaries are the immigrants themselves who are able to send home about £10 million a day, not the host nation,' he said.

Sir Andrew said that while the supporters of mass immigration were adept at publicising the 'benefits,' they studiously avoided the many downsides that result, such as the pressure on an already overburdened infrastructure, housing, health and schools as well as an increasing impact on employment and added strains on community cohesion.

The analysis shows that in the short term any benefit to the host population will depend on the distribution of income (and therefore Tax). For example, if immigrants pay more in tax than they receive in benefits, the host population will be better off.

A number of attempts have been made to measure this fiscal effect. The government's first effort which showed a net benefit of £2.5bn was based on a year in which the budget was in surplus so everybody was making a positive fiscal contribution. This study was superseded by an IPPR study which also showed a positive contribution. However the result was distorted by the inclusion of all children of mixed households (one parent an immigrant, the other not) in the host community. Correcting for this by splitting the cost of these children 50/50 produced a small negative outcome

Migrationwatch also reviewed the National Institute Economic Review No 198, the government's own calculations, an ITEM club report plus major studies in America, Canada and Holland.

'Although they used different methodologies they all point in the same direction - namely, that the benefit of large scale immigration in terms of GDP per head is minimal. Indeed, all major studies of large-scale immigration involving mixed levels of skills, such as we have in the U. K., find that its net effect is very small in comparison to GDP. If we are to have the mature and thorough debate that Ministers have been calling for let us start off with an honest and realistic assessment of the costs and benefits of the highest levels of immigration in our history,' said Sir Andrew.