Immigration and Economics - Anyone know the real story?

[the fool on the hill]

I used to believe migrants brought benefits to the UK - after analysing the fiscal side, I am changing my mind, and any further info on this would be appreciated.
In the UK, most of the work migrants are coming to do are low paid, meneal jobs. We are told they do the jobs "british people don't want to do". I cannot accept this, as before we had this recent bout of migration, we had cleaners, hotel workers, chefs and fruit pickers. The difference is, there were less of them so companies had to pay more for them. The mass immigration we have experienced has just given the same jobs to people prepared to work for less.
We have not had massive expansion (1 - 3% Annual GDP growth over last 10 years)
Also, we are told they "help the country by paying tax".....dont we all!! Tax is your "keep". Migrants get full access to roads, hospitals, and education - which all cost money. The fact many couples come here to make families surely means that overall, they have a negative impact???

[Aaron4me]

Paying people less for work will effect the middle class and poverty levels, but it also means more money in the pockets of corporations. Eventually it will come back to them though when people cannot afford to buy their product. Remember though you cannot blame those people looking for work, it is not people willing to work that is the problem, it is the corporations and the system that is at fault here. If we allow them to run our lives then slavery will be reborn again, after all this is what cheap labor is, another form of exploitation.