Neil, you comment that failure on the PM’s part to instruct under Cl. 19 doesn’t stop the Contractor notifying under 61.3 of a 60.1(19) CE. Given that the threshold for prevention is the same within the CE and Cl.19, is it not unlikely the PM would agree to the CE? If conversely he did agree, would he not be required to instruct under 19.1 at that point. - why would the Client have lost the opportunity to control/influence events? Perhaps you simply mean the opportunity is lost up until the point the 19.1 instruction comes?