common law currently living in Canada

[lisas]

My boyfriend is currently living with me in Canada and has been here for many years working in construction.  He is not legal here and since we are now together, i would like to sponsor him so that we can continue to be together and lead somewhat more normal lives.  Since he has been living here without proper documentation, i am not sure what can be done at this point in time.  Can he still be sponsored? Does he have to leave the country?  What are his chances?

Any advice would be appreciated as I hope to one day marry him.