I agree that the story in the Echo is hogwash, as per usual. easyJet's own advert though does name SEN specifically:
Primary Location: United Kingdom-London-London Southend Airport
:
https://easyjet.taleo.net/careersect...=GMT%2B01%3A00
As to how many cabin crew are involved I would say it would be less than 20 for one additional A320........