But the businessman denied funding the trip, prompting calls from Labour for Johnson to “fess up” or face a parliamentary inquiry.
Reacting to the news, Pullman tweeted: “Why can't the greedy brute pay for his own holiday?”
He then replied “absolutely” to a tweet saying: “NOBODY likes Johnson that much. The donor HAS to be expecting something in return.”
Pullman, who is best known for writing the His Dark Materials novels, which was adapted into a popular BBC show, has expressed his disapproval of the prime minister before.
In November last year, he compared Johnson to a parasitic worm.