I work in UK for a software company. I applied for a job at two other companies, 1 and 2. I accepted the offer from company 1 (after 2 months and 3 interviews) and returned the signed contract, resigning from my current job and telling company 2 I was not interested.
When I resigned, my current employer started insulting me, calling me "useless" and "incompetent". We are talking about blatantly denying any contribution I gave to the company.
I thought it was just OK to leave that, but... the new contact says "subject to satisfactory references". They wanted to contact my current employer.
Now I resigned and company 1 could cancel my new job offer because of a bad reference. Moreover, my current employer might could cost me future jobs.
Note: company 1 is not interested in contacting my other referees, all of which I am on personal, friendly good terms with and all of which are supportive.
Question: how can I avoid my current employer destroy my new job opportunity and my next ones?