There is European law that covers his, and you can drag the TV manufacturer into it and demand a fix from them. You might be able to reduce the interference by fitting ferrite chokes around the TV and router mains cable, the TV antenna cables, and the router network cable.
Am on iPad so it's hard enough entering text let alone copying links. Drop me a PM for more info.
The views expressed here are mine alone, and do NOT reflect those of my employer, present or previous.