Unite had the e-mail addresses of 11,055 employees. _And they sent a survey to these 11,055. _The number looks like it is just cabin crew - but it could be wider as just an observer says.
Included in this 11,055 was an unknown number of non-members of Unite. _How did Unite come to possess e-mail addresses of non-members? _If they are ex-members, by what right has Unite retained their data for a survey that is related to the current strike vote?
The number of responses (1,905) is such a poor response that those who by self-selection did respond are likely to be untypical of the 11,055.
My guess is that one of the ways that the mix is different is that the number of non-members of Unite who received this survey was much higher than the sample suggests. _ I would suppose that many non-members considered the survey to be invasive. _We can only guess - we will never know.