A gaffe refers to a mistake or error, especially one made in public, which can sometimes result in embarrassment or causing offense to others. Full definition
Johnson had attracted criticism in the political media for a series of gaffes in recent weeks, but amongst the wider public he was the most positively perceived of the Labour leadership. (yougov.co.uk)
But he lost in nearly every other category, his campaign faltering after he made a string of gaffes in his speeches, leading to accusations of sexism. (mirror.co.uk)
But our rotten centre - ground - seeking voting system turns politicians into constipated rabbits, afraid to say anything original, battered by press and Twitter for gaffes if they do. (theguardian.com)