The Royal College of Nursing has moved its upcoming annual conference online following “serious allegations of sexual harassment”.
The conference was due to be held in Liverpool for three days from 18 September.
The union – which represents some 465,000 health workers – said it was reviewing all safeguarding policies and procedures “as a matter of urgency” following independent legal advice.
It did not provide details of the allegations, but said it took a “zero-tolerance approach” at all times.
Carol Popplestone, chair of the RCN Council, said: “We have acted fast and took a unanimous decision that protects all attendees.
“We know that many members planning to attend were looking forward to seeing each other in person for the first time in two years.
“But this decision was made with members’ safety at the top of our minds. That is what we are here to safeguard at all costs.
“I am absolutely determined that Congress will still be its usual fascinating mix of debates, events and speeches.
“Getting together virtually won’t stand in the way of that.”