Following a recent strike against staff and budget cuts that threaten to effectively shut down the Equality and Human Rights Commission, the agency's chief executive Mark Hammond announced he will be restricting future contact with union representatives to the statutory minimum.
As a United Nations 'A status' accredited human rights institution, EHRC has a duty to monitor, advise and report to government and parliament on the human rights situation in Britain, including violations of trade union rights.
The union says the commission should lead the way and act as an exemplar employer, not rely on the bare minimum allowed under the law.
The commission is pushing through a 63% budget cut and a 72% reduction in staff by 2015, compared to 2007 levels. These will hit the agency's helpline, grants function, mediation, legal casework, and its work with communities.
Votes of no confidence in both the EHRC's senior managers and board of commissioners were carried overwhelmingly by PCS members at their recent annual meeting.
PCS and Unite members will protest outside the commission's five main sites in Birmingham, Cardiff, Glasgow, London and Manchester on Tuesday 13 March between 12pm and 1pm.
Most of the staff - who say they will oppose any attempt to undermine the colleagues they have elected to represent them - are low paid advice workers and caseworkers.
The protests come on the day MPs are expected to debate the use of highly-paid consultants in the civil service and its agencies - a major cause of concern at EHRC.
The BBC Radio 4 investigative programme File on 4 will today report on the controversial issue of the pay and tax arrangements of some senior public servants.
PCS general secretary Mark Serwotka said: "It is nothing short of shameful that this internationally recognised human rights body is trying to cut its elected trade union representatives out of the picture.
"Instead of threatening our reps, the chief executive, and the senior managers and commissioners, should be talking to us about our genuine concerns for the future of the commission and its vital work in preventing and protecting people from discrimination and hatred."
To find out more see the PCS website: www.pcs.org.uk.