There are people who have called it shirk, but I dont see how it can be considered a tawheed vs. shirk issue. Many senior scholars have called it bid'ah or impermissable but I have yet to come across any senior scholar say it is shirk. See this other thread: http://www.sunniforum.com/forum/show...ke-dua-for-you Sh. ibn Uthaymeen and Sh. Bakr Abu Zayd considered it bid'ah. And amongst the Deobandis there seem to be different views. Mufti Taqi Usmani and Ml. Ashraf Ali Thanvi say it is not permissable to ask the dead for du'a. Ml. Yusuf Ludhianvi and Ml. Rashid Ahmed Gangohi also say it is not permissable but the Prophets are an exception to this. So they state it is permissable to request the Prophets for du'a.