A primary school teacher will launch a challenge against Education constituency candidate Cheung Man-kwong today. A supporter of Lee Sze-yuen, who teaches at St Edward's Primary School in Lam Tin, said he was joining the fray to push Mr Cheung into more commitment on education matters instead of concentrating on politics. 'We are not going to win, but we want to provide an alternative and speak for teachers who have been silent,' teacher Chiu Sin-on said. 'Mr Cheung is a person of high calibre, but we really hope he could do more for the profession.' Mr Chiu cited work pressure on teachers as one of the issues Mr Cheung should look at. Mr Lee is a member of the Professional Teachers' Union, of which Mr Cheung is the chairman. He will submit his nomination this afternoon.