The delay is because they moved all files from islamabad to London and they didnt start processing until all files are transferd, secondly london is a very busy office it process applications for middle east and some other countries as well so they have loads of applications which is causing so much delay for everyone.
Its not just your file they have moved so many files and one is yours, actually they shouldnt move your file becuase you already did the medicals but its immigration you know, dont worry you will hear some new soon, send the email enquiry to london office if you havent done so.
