Until June 2010 you could use substituted documents for proof of English language, but from June 2010 onwards IELTS is compulsory for all principal applicants in Federal Skiller Worker class.
My wife and I were both born in England and have lived here all our lives. My wife has a Bachelor's degree and a doctorate (PhD) both from English Universities and I also have a degree from an English University.
And my wife still had to spend the £108 on the IELTS test proving to Canadians that we English people can speak English!
So if we have to do it, so do you!
Wayne.