As Labour and the LibDems push for an amnesty for Illegal immigrants, I take a quick look at a paper released by MWUK (Migration Watch UK)
The True Cost of an Amnesty for Illegal Immigrants
IPPR claim that;
research shows that regularising the nearly half a million people who currently live and work illegally in the UK could net the Treasury around £1billion a year
However MWUK have pointed out;
Their figure of £1billion of income is their best case - their Factfile gives a range of income figures, the lowest being £485 million and the highest being £1038 million.
It is incorrect for the IPPR to use the average wage of £308 figure because this is based on all recently arrived immigrants, including those from fully developed countries. For example in calculating this average the IPPR have included immigrants from such developed countries as the USA, Sweden, Australia, France and Belgium. Clearly, including these countries increases the average wage to a level higher than the wages earned by illegal immigrants.
The IPPR have taken absolutely no account of the additional expenditure involved, for example, Tax Credits, Unemployment Benefits, Child Benefit, Housing Benefit, Education and Health. 
The Migrationwatch analysis shows that, rather than generating income for the Treasury, an amnesty would cost the taxpayer, between £0.8 billion and £1.8 billion a year.
So ... It’s more Labour spin, trying to trick us to take ever larger amounts of people to help their friends in Big Business make another million.
jenray
Pro 
I think immigration is with us now big time and a sensible solution has to be found that doesn't make the indigenous people of the host country fearful for their own well being and the immigrant certain that they're not going to be exploited and abused when they arrive seeking work and a better life...the sad thing is that they cannot get that at home, which is obviously a much better solution all round, but that would take many, many years to achieve in some of the poorest countries on earth...if this country and most other of the more affluent European countries and the USA have serious illegal immigrant problems, what else can you do other than to say let them stay and allow them to become legal citizens rather than falling through the net and being treated like flotsam and jetsam, and prey to the worse kind of exploitation and abuse...in the UK, hundreds of thousands of us are now emigrating to the warmer countries, and we expect to be treated with respect and courtesy, and not to be considered as a problem for the host country...if this mass immigration continues, all these countries are going to start reconsidering how much they can offer the newcomers, as with France withdrawing free health care for people under fifty, and Spain will probably have to do something similar eventually if the flood continues unabated as expected...trying to work out the financial rewards or losses I think in the end is a futile exercise...it's just got to be done because there's no other alternative...well, yes, there is, leave them as illegals and all that that entails...not a choice in my books...