Retention of Legal Obligations

23.4  Despite the Contractor's right to sub-contract pursuant to this Clause 23, the Contractor shall remain responsible for all acts and omissions of its Sub-contractors and the acts and omissions of those employed or engaged by the Sub-contractors as if they were its own.  An obligation on the Contractor to do, or to refrain from doing, any act or thing shall include an obligation upon the Contractor to procure that its employees, staff, agents and Sub-contractors' employees, staff and agents also do, or refrain from doing, such act or thing.