LONDON (Reuters) - Implementing a deal between Greece and other euro zone leaders over its debts is a task that should not be underestimated, a spokeswoman for Prime Minister David Cameron told reporters on Monday. "Clearly the challenge now will be on delivering on that and the implementation which lies ahead ... and I don’t think we underestimate the size of that challenge," the spokeswoman said. "We are glad an agreement has been reached but there is still more to do." (Reporting by Kylie MacLellan; Writing by William James; Editing by Andrew Osborn)
