We expressed our concern to HS2 Ltd for the potential for the large main contractors to pass any financial consequences of contract renegotiations down the supply chain to the small and medium–sized enterprises, of which HS2 Ltd told us there were around 2,400, who may find it more difficult to absorb such changes. HS2 Ltd acknowledged this issue, telling us that it will take this into account as part of its renegotiations and commercial management.35 Environmental obligations