Because while I work for a British company the shares are awarded by our French HQ, so unfortunately none of those share planes are available in this case. The company employs 50k+ people globally and only HQ awards shares.

Also I'm not sure how much tax this would actually save - you can only get £3600 worth of shares tax free per year on the employee incentive plan(which seems closest to what I'm getting, flat number of shares after 4 years). That's a very....low amount.