Research alternative approaches and ask your project lead to suggest another way that would achieve the same end in a different way. Develop a couple of alternative plans and evaluate the merits and downsides of each before deciding how to proceed.

Respond with facts and figures of where this particular tactic has worked in the past to show that your presentation and reasoning is sound. In addition, build a plan and outline improvement targets which can be monitored on a regular basis ensuring that any feedback is actioned.

Ask him to be specific about his concerns really getting to the bottom of his issues. Make sure you have fully understood why he objects so you can address those worries. Share with him your personal experience in order to generate an open dialog which really gets to the heart of his feeling.