Peter Burt, who served as an RNLI officer in Poole for 13 years, told the BBC that lifeboat crews must always help people in distress at sea. This comes as the charity remains central to a heated immigration debate.
Mr Burt, a former launching authority at Poole lifeboat station, said the RNLI cannot "differentiate between who they should rescue and who they shouldn't rescue." He added, "You can't just leave them there to die."
The charity's headquarters in Poole, Dorset, have been the site of protests, and some volunteers have reportedly faced abuse, including being called "traitors" in social media footage. Last week, the RNLI museum in Poole closed after its volunteers were targeted by anti-migrant protesters.
Neil Duncan-Jordan, Poole's Labour MP, acknowledged the need to prevent illegal migration but stated that it is not the fault of the RNLI. He urged respect for the charity's personnel.