No, I don't think it is the
Hornet Robberfly, Pauline. To tell you the truth, I'm never too confident at ID'ing these and similarly I've spent about 15mins comparing this to any of the so-called
Kite-tailed Robberflies - but can't find a good match so far.
The
Hornet one is more orangey as opposed to grey, IMO and has nice dark markings on the wings. Keep looking though!