It would be “a step too far to require office managers to censor Christmas cards”, a government department in Northern Ireland was advised in a legal opinion on a row over a Sinn Féin Christmas card in 2004.

A declassified file released on Tuesday by the Northern state archive reveals some staff at the social security office in Coleraine, Co Derry were “offended” by the card and requested that it be removed.

The card was sent by the Sinn Féin office in the nearby town of Kilrea and bore “a message to the effect, ‘thank you for all your help and support over the year’.”

In a letter dated December 23rd 2004, Dermot MacLennan, branch vice-chairman of public service union Nipsa, wrote that “many branch members have indicated how offended they are that this item has been on display.

“In an age where staff have been advised, in no uncertain terms, that sports tops and sporting paraphernalia are not permitted in the workplace, staff are incredulous of the insensitivity and lack of understanding displayed by management in this matter.”

He said it was an “insult” to suggest that any of its members were not impartial, and “if the card had come from the political wing of a loyalist terrorist organisation, the same staff who have asked for removal of this card would be asking for the removal of any other”.

According to an undated note outlining the background to the controversy, the card was displayed with all other cards received by the office, including those from voluntary groups, the Police Service of Northern Ireland (PSNI) and other government bodies.

A member of staff and a trade union representative asked the branch manager to remove the card, but after consultation, she decided the card would remain “as it was felt it was only a display of gratitude from an elected representative and offence should not be taken, as after all staff gave advice to all sections of the community and this was an acknowledgement of their work”.

The manager subsequently discovered the card had been removed, and emailed staff “expressing her disappointment” and reminding them “as civil servants, we are expected to serve all sections of the community with total impartially [sic].”

In response, she received an anonymous letter from a member of staff stating that the email “is made to make the staff feel like bigots, however this is not the case.

“After all we are told not to bring anything political into the workplace and yet management decide that a Christmas card from a political party is OK as a card was being displayed from the PSNI.”

The Department of Social Development subsequently sought legal advice, which was provided on January 11th 2005.

“This is an “extremely sensitive area but in my view the manager acted correctly,” the departmental solicitor concluded.

“The need to provide a neutral working environment in which both sides of the community feel comfortable necessitates the current rules against Celtic/Rangers jerseys and other sectarian paraphernalia.

“However, that policy can only go so far. This was not a Sinn Féin poster or a Sinn Féin calendar. It was simply a Christmas card which happen [sic] to come from a Sinn Féin branch on behalf of an elected representative and was no doubt one of many Christmas cards received by the Social Security Office.

“It would in my mind be a step too far to require office manager to censor Christmas cards to ensure that none of their donors was an individual who might possibly offend one or more members of staff.

“That is an entirely different issue from ensuring that members of staff themselves do not engage in any conduct within the workplace which makes, or could make, their colleagues uncomfortable,” the solicitor concluded.