Suggest you contact Building Control at Lewisham Council (see website for details). If you are worried about the safety of the building they have the power to stop the work; they also have to approve plans and then inspect when the work is done. Their job is to make sure that buildings don't fall down!
Tell them about the damage to the kerb, road etc. Contractors have a duty to clean up the road and pavement after any building work, skips etc. and make good any damage.