No, definitely local labour...the RAF had a lot of problems with them being unwilling to work after various follow-on raids in August, and five locals from the Romney Marsh area were killed during a raid on Lympne, including what appears from their headstones to be a pair of brothers.
The Air Ministry also had a scheme pre-positioning repair teams centrally in depots between clusters of airfields...but the problem on 12th August seems to have been the sheer amount of damage done at Hawkinge, Manston and Lympne - buildings damaged or destroyed, hangars damaged, holes in flightlines needing filled etc. - overl;oading their plans locally, it required an extra 350 workers in total at Manston, for example.