According to this document:
https://www.raildeliverygroup.com/component/arkhive/?task=file.download&id=469762587
a prior reservation of a wheelchair space will "Where available, train staff will also assist you if you need a wheelchair space and make sure other customers do not block the area with their luggage; they can help with food and refreshments from the buffet, or simply alert you when your station is coming up".
This suggests that it is the role of the train staff (not station staff) and they are authorised to have luggage moved.
Station staff may help with the installation and use of the ramp.