British man Abu Layth al-Khurasani was killed in the past few days fighting for Islamist forces in Syria.
His friends paid tribute to his "martyrdom" on Twitter and Instagram.
He sent his last tweet on January 30th, writing: "Turkey are now actively aiding FSA on the borders of Al Ra'i, there are two Turkish tanks guarding a checkpoint close to the town."
More top news
British soldiers will join troops from some 30 countries who work in the country.
The demand comes after the Prime Minister urged a "grown up" relationship between her government and the devolved administrations.
The rapper failed to make it to London in time as he had problems with his passport.