The RSA have reportedly rebuffed three attempts by staff to organise with the IWGB.
A leading UK arts charity is engulfed in a row with workers and trade unionists over a recognition agreement which would see staff given representation.
Last week it was reported that almost half of staff below senior levels at The Royal Society of Arts (RSA) have joined the Independent Workers Union of Great Britain (IWGB), with a petition indicating most staff backed unionisation.
Staff members claim that three attempts to achieve union recognition have been rejected by the RSA.
Fellows of the RSA appear to have taken the side of staff, with an open letter signed by more than 58 fellows calling for the RSA to immediately re-initiate a positive process towards voluntary recognition.
An RSA spokesperson told the Observer: “As we have said throughout, our strongly held view … is that a truly representative, democratically elected staff body is the right way to secure a staff voice. We have acted throughout this process in ways to ensure this outcome.
“We have an exceptional group of staff who care passionately about our work, reputation and heritage and we are grateful for their ongoing commitment to our compelling societal mission.
“We will be holding a series of open sessions this week, to provide our people with clarity and support.”
The RSA Union, who are organising within the IWGB, responded by saying that despite alleged efforts to disrupt unionisation, workers are steadfast in their goals.
Posting on Twitter, the union said: “Staff have faced a backlash from management that included a member of staff being asked not to return to work and staff receiving another telling off.
“Staff have also been told not to put anything on social media or risk being in breach of contract. Despite this, we have seen an increase in IWGB union membership since last week.
“As a union, we have been overwhelmed by the outpouring of public support, particularly from Fellows, who we encourage to remain with RSA, which is made better by them working with us in our campaign for change.”