Unite boss to face leadership challenge amid concerns over rise of Reform

Simon Dubbins to announce he has secured required number of nominations to challenge Sharon Graham

Sharon Graham, the leader of the UK's second biggest union, Unite, is to face a challenge as general secretary over claims the union is not doing enough to challenge the rise of Reform UK.

Simon Dubbins, who started out as a print worker and has been an international director with the union since 2008, will announce on Tuesday that he has secured the required number of nominations to mount a challenge.