New Delhi, Dec. 30 -- The U.K. prime minister is facing criticism after he celebrated the return to Britain of a human rights activist who was recently released from an Egyptian prison but whose past social media posts apparently contained violent and antisemitic language.

Successive British governments have campaigned for the release of Alaa Abd el-Fattah, a dual national who had been imprisoned in Egypt for most of the past 14 years. He returned to the U.K. on Friday after Egyptian authorities lifted a travel ban that had forced him to remain in the country since he was freed in September.

But a senior member of the opposition Conservative Party on Saturday criticized Prime Minister Keir Starmer for giving a "personal, public endorsem...