I had applied for a position at 2 universities. University A (UA) and University B (UB).
UA performed their processing after the application deadline very quickly and sent me an invitation for interview. I went for the interview and was selected. They notified me via email and sent me an offer via email which stated the salary and the contracted term. I replied that I am happy with this and would like to accept the position. They also took a copy of my passport last week and said they would like to start processing my Tier 2 visa. They also sent a hard copy of the contract to my address and asked me to sign and return it by the 1st of October. I have not yet signed the contract.
Now during this time, UB shortlisted me and sent me an invitation for interview. I went and gave the interview at UB. I was notified recently that I have been selected and they have offered a pay that is substantially higher than what UA has offered me and also their contracted term is longer than UA.
Now naturally I would like to go with UB.
So my question is, Can I, at this stage request UA to stop working on my case and that I would like to withdraw my application from them. Is it too late since they already said they were going to sponsor my Tier 2 visa?