From Longman Dictionary of Contemporary Englishsoapboxsoap‧box /ˈsəʊpbɒks $ ˈsoʊpbɑːks/ noun [countable usually singular] informal PPSAY/STATEif someone is on their soapbox, they are telling people their opinions about something in a loud and forceful wayon your soapbox Environmental activists have climbed on their soapboxes to protest the president’s action.
Examples from the Corpus
soapbox• My first memories of a Leeds match were standing on a soapbox with my dad, when we scored a goal.• With his wife Norma beside him, he climbed on to a soapbox to put across his campaign message.• Nor do the parties offer their constituents soapboxes on which to air their views.• That led to the idea of a dedicated electronic soapbox on the issue.• Unlike John Major and his soapbox, it is not part of the image.• The Prime Minister was on his soapbox.• But last Saturday Major climbed on to that soapbox in Luton.• He was the soapbox orator who could quote Virgil or Shakespeare to give dignity to a bitter grudge.on your soapbox• Share a professional concern with a close confidante or intimate Saturday, but come Sunday you must get on your soapbox.• The Prime Minister was on his soapbox. 