

He’s a member of the cabinet and so should know the government position. He can also state if UK forces acted in any part of the operation (e.g. refilling).
The decision may not be his but he should be enacting the effect of the decision. It’s absolutely reasonable to ask him.
How did this manifest before? You only need to look at the advertising of the time. Take the 1950s America - McCarthyism and the red scare in full force. Most US marketing relied heavily on how buying American made you a good patriotic citizen, living the American dream… even if the product wasn’t 100% American.