Chief executive Mark Dowie said "decent people" see it as "humanitarian work of the highest order". He said he had to speak out after volunteers for the charity reported being abused and crews also described facing an "angry mob" after coming back from a rescue.

       A London RNLI crew hit out on social media at the weekend after volunteers were abused. Some members of the public were shouting at the migrants: "Go back to France."

       It comes as record numbers of migrants try to cross the potentially treacherous English Channel to get to the UK, despite vows from the Home Office to make the route from mainland Europe "unviable".

       An angry Mr Dowie said the charity was "doing the right thing" by going to people's aid. He said: "All decent people will see this as humanitarian work of the highest order.

       "Our crews should not have to put up with the abuse they received."

       He said migrants' dinghies were often overloaded and inadequate for the perilous journey, with people suffering exposure, dehydration or other sickness.

       Some spend more than 30 hours trying to reach the British mainland.

       He acknowledged the migrant crisis was a divisive issue, but said RNLI volunteers simply wanted to prevent people dying at sea.

       He said: "We've seen life jackets made from empty lemonade bottles, women and children, young men, old men, with no life jackets, in the middle of nowhere, with ships going past just hundreds of yards away."

       He added: "It's a very polarising issue.

       "The humanitarian side has not really been told properly."