Maybe try Google Flights. They show you what is availalbe for ALL airlines that fly the routes except Ryan and Easy I believe:
https://www.google.com.au/flights/#search;f=LHR,LGW,STN,LTN,LCY,SEN,QQS;t=LEN,EEU;d=2017-06-25;r=2017-06-29;tt=o
There are direct flights into Leon.