The debate over whether the doctrine of lawful act duress exists has been settled in the affirmative by the UK Supreme Court in Times Travel (UK) Ltd v Pakistan International Airlines Corpn. However, the elements by which one establishes lawful act duress was the subject of disagreement between Lord Hodge (who delivered the majority judgment) and Lord Burrows. The disagreement stems from how illegitimate pressure should be constructed. Should illegitimate pressure be ascertained from all the circumstances—without the necessity for a more detailed analytical structure? Or given the lawful nature of the threat, should one focus on what renders the demand unjustified, and require proof of a bad faith demand and conduct which created or increased the victim’s vulnerability? We examine the debate over the existence of the doctrine, how it should be analysed, and how the answers are impacted by the existence of other legal controls over bargaining power and the value placed on the freedom of contract.