The committee decision follows discussions at regional and national level, and a consultation of UNISON members who are affiliated to the Labour party. The consultation was carried out online.
UNISON general secretary Dave Prentis said:
“Jeremy Corbyn retains the backing of a majority of UNISON’s Labour supporting members. That’s why the committee supported his nomination again.
“However, a significant minority backed Owen Smith. Their views will always be respected in our union- that’s our proud tradition.
“It’s healthy for people to hold alternative views on the future direction of the party. What’s toxic though is for abuse, threats and aggressive language to be considered acceptable- or the norm. Labour is in danger of becoming the new ‘nasty party’ if this behaviour continues unchecked. There’s no place in the party for witch hunts against MPs, councillors and party staff.
“The decent hard-working people we represent don’t want a party riven by infighting. They want a united opposition that stands up for public services which are facing intolerable pressures.”