If anyone cares to Google luton centuary park they will find the following statement on a pdf
Outline
Parm was commissioned by Luton Borough Council,
to investigate the potential feasibility of an ADZ/TIF
scheme to fund circa £76M of infrastructure required
to not only release 2,845,500 sqft of commercial
development (80% B8) on 194 hectares (479 acres)
and to facilitate the potential future expansion of
London Luton Airport to enable it to accommodate
24M passengers
First time I have seen that figure mentioned.