With the UK's last-minute decision to participate in the European elections, British political parties are scrambling to get their campaigns underway.

And the pro-EU Liberal Democrats are not mincing their words - launching their campaign with the slogan: "Bollocks to Brexit".

Fresh from a strong showing in local council elections, the opposition party posted a photograph on Twitter of its leader Vince Cable with a "special edition" of its manifesto for the May 23 European parliament vote.

The word "bollocks" is often used as a synonym for "nonsense" in colloquial British English.

"It is an attempt to put in a more pungent way what a lot of people think actually," 76-year-old Cable told broadcaster ITV.