Universal backpay and pip assessment tribunal

I naturally migrated to UC in August 2018 and had been in receipt of esa with sdp and pip. I recently had my second pip assessment and the report is full of lies. Completely different from my first time successful 2017 pip assessment, although no change in my lifelong conditions. I am awaiting the confirmation any day now of having pip rejected, based on the report and then will write the mandatory reconsideration and then on to the tribunal. My question is, will I lose the reported backpay for loss of sdp during my no choice switch to UC? DWP are dragging their feet and I'm worried that the timing will again mean i miss out.

Hi Gordon,
If i had Pip reinstated, would i then receive sdp ongoing payments on UC? I ask as I am worried that I'll miss out due to bad timing such as missing by few months not being transferred to UC in the furst place.

Thanks Gordon
I hope that i win my pip back and get natural migration ongoing payment. The whole brexit mess shouldn't have punished the disabled and what exactly are the likes of Rudd actually doing? Its a total joke