OK, to be fair, the US simply didn't have any crewed space launches between 1975 and 1981, that probably goes a long way to explaining this disparity. But still, once they started taking foreign citizens with them, I would have thought that Britain would be among the first on that list. Between 1984 and 1985 there were a Canadian, a Saudi, someone from the Netherlands and a Mexican, and then there was a long pause until 1992, presumably because of the Challenger disaster.
"Woman from Mars goes to space!"
It is sold out...
"I want to be a space astronaut, go to outer space and discover things that have never been discovered!"
"Look, you're British, so scale it down a bit, all right?"