What do British people call a vacuum cleaner?

THE British nominally call it "hoover." But that's a little misleading (see below). This is because back in the 1970s, half the people in the UK were calling it a "vacuum cleaner" (or "the vacuum" or just "the vac").

We can hear "vacuum" or "vacuum cleaner" several times in the movies Get Carter (1971, starring Michael Caine) and Sitting Target (1971, starring Oliver Reed) -- both MGM films that aimed to give an "authentic" flavour of UK of the time for the international (especially American) audience.