Ok, I have gone through the interview stage with a Big 4 and given I worked as a contractor over the last year, have been asked to provide some proof of my work. I initially agreed and then realised that this is still an ongoing project and a highly confidential due diligence. I believe it is unethical for them to ask that, on the other hand, I would love to show what I have done, it would support my application. Over all this, I am loosing interest in actually working there...what's your opinion?Shall I give in, compromise myself and just ignore my confidentiality agreement? And likely forget the job as well then? Indeed I have challenged them and asked if the partner who wants to see my work, will sign a confidentiality agreement as well?

Do not reveal client specific information, describe your role, responsibilties, technologies and all nonsentive information etc ... All companies take confidentiality seriously therefore you dont want to shoot yourself in the foot by showing all your cards. Alongside with the non project specific information, you could provide them with reference contacts for your direct managers in this project who could put in a word for you, and if they reveal sensitive information then you could not be blamed for it really.