Foreign Secretary Yvette Cooper has launched a review into what she calls "serious information failures" in the case of British-Egyptian activist Alaa Abd El Fattah.
In a letter to the Foreign Affairs Select Committee, Cooper said she, Sir Keir Starmer and Deputy Prime Minister David Lammy "were all unaware" of Mr Abd El Fattah's historical tweets, which they consider to be "abhorrent".
It comes after the Conservatives and Reform UK called for the activist to be stripped of UK citizenship and deported after social media posts in which he called for Zionists and police to be killed resurfaced.
Mr Abd El Fattah has apologised, saying he understood "how shocking and hurtful" the posts were.