Crew on board a RNLI lifeboat were heckled and impeded as they prepared to enter the English Channel to seek and rescue migrants making the perilous crossing.
A caller to UK radio station LBC said she was on the beach in Hastings when angry protesters started abusing the lifeboat charity workers and even stood in a line in front of the rescue vessel to prevent it from launching.
“It was really upsetting, and you could hear the hatred in their voices,” she told presenter James O'Brien.
Among the torrent of abuse hurled was a demand not to “bring any more of those home, we're full up".
One protester told the crew he had stopped donating to the charity because of their daily rescue missions.
The RNLI corroborated the incident in a statement.
“We can confirm an incident was reported to the police. The lifeboat was able to launch and the station remains on service,” it said.
Tensions rise on England's south coast
The incident came just days after 27 people drowned in the Channel while trying to reach Britain.
The migrants perished when their boat was struck by a container ship.
A vigil was held in UK port Folkestone last week to remember them.
Far-right group Britain First has previously been condemned for organising patrols to repel migrants attempting to land on the Kent coast.
The vigilantes are in opposition to Channel Rescue, a collection of clifftop spotters who seek to assist migrants they spot.
Feelings on both side of the divide are feverish, in part due to the rapid escalation of illegal crossings made in 2021.
The monthly number of crossings rose steadily until September, when it reached 4,653.
In October only 2,669 made the journey, but to date the figure for November has reached a hefty 6,665, Migration Watch UK told the UK last week.
With winter approaching, the numbers are likely to decrease in the coming months, but without a plan to address to the UK's asylum problem, the confrontation on the UK's southern coast will only intensify.