When you received your initial clearance at Belfast, your clearance would have been to EGPF, therefore, your clearance limit is Glasgow!!!.
As controllers, in the event of RT fail, we would expect you to follow the STAR o.e to LANAK, and then proceed to the GLW and make an approach to the rwy in use, adopting the RT fail procedures.
The answer to your question though, is your clearance limit is Glasgow.