When can a lawful threat constitute economic duress? It seems like a simple enough question, but it is one with which the courts have continued to struggle. The Court of Appeal in Times Travel (UK) Limited v Pakistan International Airlines Corporation [2019] EWCA Civ 838 (TT v PIAC), has recently given some guidance on when a lawful threat will not constitute economic duress. It held that a threat made in good faith, but potentially unreasonably, by a company in a monopoly situation did not constitute illegitimate pressure for the purposes of economic duress. Referring to CTN Cash and Carry Ltd v Gallagher Ltd [1994] 4 All ER 714, the Court of Appeal emphasised that whilst lawful act duress is possible, it would be ‘unprincipled to develop the doctrine of economic duress as a means of controlling the lawful use of monopoly power’ [107].