The phrase "blatant untruth" means a very obvious and blatant lie or falsehood.
Sentences with «blatant untruth»
You should proofread to avoid grammatical and spelling errors and typos, and steer clear of exaggeration as well as using blatant untruths. (resume-now.com)
These statements were both blatant untruths. (firstthings.com)
She also boldly accused Leadsom of telling «a blatant untruth» about how many UK laws are made in Europe. (totalpolitics.com)