Mr. Healey (perhaps Lord Denis Healey) was a British political figure. After the attack of the alien monster his name was mentioned in the news from London, expressing the reaction of his country about that tragic event.
Only Healey's surname is mentioned in the book, and the fact that he is stationed in London. The historical context suggests that he is a British politician, although his capacity is not mentioned. The identification with Denis Healey, a former Secretary of Defense who was active during the 80s, is a possibility.