ObjectivesIn the United Kingdom, three people die every day awaiting an organ transplant. To address this, Scotland and England plan to follow Wales and introduce opt‐out donor consent. However, emotional barriers, myths, and misconceptions may deter potential registrants. Our objectives were to estimate the number of people who plan to opt‐out of the donor register and to test whether emotional barriers (e.g., medical mistrust) differentiated participants within this group. Finally, in an experimental manipulation, we tested whether intention to donate decreased by making emotional barriers more salient and increased following a widely used myth‐busting intervention.DesignMixed between–within design.Methods UK residents (n = 1,202) were asked whether they would choose opt‐in, deemed consent, or opt‐out/not sure if legislation changes to opt‐out. Participants also completed measures of donor intentions at baseline, following a 12‐item emotional barriers questionnaire and again, following a 9‐item myth‐busting intervention.ResultsFindings indicate that 66.1% of participants selected to opt‐in to the donor register, 24.3% selected deemed consent, and 9.4% selected opt‐out/not sure. Emotional barriers, notably fears surrounding bodily integrity, were significantly elevated in participants who selected opt‐out/not sure. Increasing the salience of emotional barriers reduced donor intentions in the opt‐out/not sure group. However, dispelling organ donation myths did not increase intention within this group.ConclusionsIf opt‐out legislation is introduced in Scotland and England, approximately 10% of participants plan to opt‐out or are not sure. Dispelling organ donation myths with facts may not be the best method of overcoming emotional barriers and increasing donor intentions for those planning to opt‐out. Statement of contribution What is already known about this subject? In the United Kingdom, three people die every day waiting for an organ transplant. Although 90% of the UK population support organ donation, only 38% are registered donors. To address this, Scotland and England have recently proposed to introduce an opt‐out system of donor consent. To date, limited research has investigated public attitudes and intentions regarding opt‐out consent laws in Scotland and England.Emotional barriers (e.g., medical mistrust) are key factors that may deter potential registrants. However, no research has examined these barriers in relation to proposed opt‐out consent laws.Myth‐busting is widely used around the world as part of campaigns promoting organ donation. The NHS currently use a myth‐busting feature on their webpage to dispel harmful myths about organ donation; however, there is limited evidence of the impact this has on intentions to become an organ donor. What does this study add? Approximately 10% of UK participants plan to opt‐out or are unsure of their decision, if the law changes to opt‐out.Emotional barriers, notably, bodily integrity fears, are significantly elevated in people who plan to opt‐out.Increasing the salience of emotional barriers reduced donor intentions for people who plan to opt‐out.A myth‐busting intervention had no effect on donor intentions for people who plan to opt‐out of the donor register.