Labor's immigration spokesman Richard Marles has been bumped off a VIP jet flight to the Manus Island asylum seeker detention centre after Labor supported a new inquiry into the centre operating on Nauru.

Immigration Minister Peter Dutton, who will inspect the Manus Island facility on Tuesday, had offered Mr Marles a seat on the plane, but the offer was withdrawn 24 hours after Labor backed the Senate inquiry.

Labor's immigration spokesman Richard Marles. Credit:Alex Ellinghausen

No reason was given for the decision late on Friday, but it came after Mr Dutton's office attempted unsuccessfully to persuade Labor to oppose the inquiry, which will investigate whether the Abbott government is meeting its duty of care to detainees.

The inquiry was prompted by an independent report by former integrity commissioner Philip Moss that found evidence of rape, sexual assault of minors and guards trading marijuana for sexual favours from female detainees inside the Nauru centre.