On 3 July 1988, the locomotive hauled the "Mallard" 50th anniversary special from London King's Cross, along with the return journey. The locomotive began regular passenger service from London King's Cross to Peterborough on 15 July 1988. As the development of the ECML Electrification continued, the engine was painted into the new style InterCity Swallow livery and named "Avocet", in recognition of the Royal Society for the Protection of Birds (RSPB), by Prime Minister Margaret Thatcher on 16 January 1989 at King's Cross station. After the ceremony the locomotive hauled a special train conveying the RSPB president Magnus Magnusson, along with other VIPs, to Sandy. Passenger use continued on the ECML until 5 March 1989, a week before the Class 91s entered service on the diagrams.