It has closed unfortunately. Classic case of high running costs and low customer numbers/spend. There is a note on the window that mentions these things, but doesn't mention Sainsbury's or Tesco. However I am sure their proximity must have contributed. The owner still has a shop in Queen Elizabeth Street (nr. The Circle) though and most of the staff I believe went over there, which is something.
It is a great loss to this end of TBR though. I work very close-by and can't just nip out for a sarnie or can of pop.
Shame... it was a much nicer store to shop compared to Sainsburys. The wierd thing was that despite it being huge, the pokey little shop on the other side of the road was always much busier. I often went to the smaller shop because crossing tower bridge road is a nightmare.