Should I renegotiate my offer price after survey points to problems?

I’m thinking of asking the vendor to rectify the faulty damp-proofing or perhaps I can get an allowance from my mortgage lenderQ My girlfriend and I are in the process of buying a flat. We have had an offer agreed on the property and our survey has been conducted which has shown up a few worrying problems:
•the damp proof injection course has failed by the back entrance leading to a 100% saturation reading;
•the electrics are faulty and need a rewire and there are also sockets in