I'd suggest chase them up. No harm in dropping an email asking for their feedback. Even if you weren't successful you need to know for sure so you can get closure and focus on the others. Good luck!

I think then you should be careful about upsetting folk at Uni A by accepting and then changing your mind if they have any connections to Uni B, as it may not give a good impression. What about explaining the situation to Uni B in the chance that they could make your funding a bit more concrete and then you could make a better decision about whether you would like to do the PhD at Uni A or Uni B?

see below

Also consider chasing up Uni B to see how likely it is you will get funding. If there is a fair to good chance, go for Uni B, where you know the supervisors and will have more chance of a positive PhD experience.
Humble opinion of fellow PhD applicant.

Thank you for all for replying... It was amazing to sign in on here and read these responses. It was very encouraging to know that there are other people who have been in the same boat.

There are aspects of the project that I certainly would enjoy. The support and facilities would be very good. My relationship with the supervisors is good. So I am going to continue and see what the outcome will be.

Cheers!

I 100% want to do a PhD in my chosen field (engineering). I've applied at the uni where I did my undergrad - an excellent London university - for funding (with the Economic Social Research Council). I have been been shortlisted for interview. My supervisors are extremely keen as I am strong candidate. I have a dilemma as I do not feel passionate about the specific topic (they wrote the proposal and I got on board later). It has been nagging me since day one but I went with the flow. If I back out now will it harm my references? Or if I continue to go with the flow and then get offered the funding and back out, would that be even worse? I want to be able to apply at UCL again (and other unis - with decent references from my UCL advisors) - am I blowing my chances? Any advice PLEASE!!!

I know I should have spoken up sooner but I did not have as much insight as I do now and thought I had better just take the opportunity.