I'm in the exact same position and seeking to discover a new UK controlled broker. Most seem to be MM spread gambling brokers and not many ECN brokers.
Narrowed it down to FxPro and FX UK. Both have been around some time and seem legit STP/ECN. includes a Raw account plus commission but not certain on the spreads.
Edit: It states of FPA which canceled trades of alot of clients due to an EA they had been using this took advantage of price delays.