Flybe are operating a charter for Neilson / Thomas Cook from Southampton to Lleida this winter every Sunday as well.
The only difference, is that flight times this winter are about 20 mins later than those you mentioned.
SOU 0750 ILD 1120 BE9917
ILD 1205 SOU 1335 BE9918
If anyone knows a way to book a seat on this flight without buying a 7-night holiday, please tell me - I've spent ages on the phone to Neilson, Thomas Cook and Flybe in an attempt to get a seat but to no avail