Sqeeling/grinding when I slow down

Hi everybody

I have a 96 106 escapade 1.1l and when I am going along at a decent speed (40-60) and then lift my foot off the accelerator (not hitting the break), I hear a squeeling grinding vibrating noise from the front (right I think) of the car. As soon as I put more pressure on the accelerator and speed up again, it goes away.

Does anyone know what this could be? And how serious it is?

Thanks.