Grant Adamson, 60, was told to remove the 30ft statue from outside his shop in Wigan in 2022 but reinstated it two weeks ago to spread ' Christmas cheer'.
It urged the UK and Mauritius not to ratify the agreement under which the UK would pay to lease back the strategically important Diego Garcia air base.
The stunt by the Lib Dems will now go to another debate and vote after their support - and that of the Deputy Speaker - allowed it to pass by a single vote.