It is widely reported that the Communication Workers Union will appear in the High Court on Friday seeking an injunction preventing Royal Mail from hiring temporary workers to help to break the postal strikes. Even if the CWU succeeds, though, its victory is likely to prove pyrrhic.

It is a criminal offence under regulation 7 of The Conduct of Employment Agencies and Employment Businesses Regulations 2003 for employment agencies (such as Reed or Office Angels) to supply temporary workers to fill in for employees who are on strike. As it happens, no successful prosecution has taken place under this regulation but that does not mean it can be ignored.

So if Royal Mail approaches an employment agency to ask it to supply temporary workers, it is aiding and abetting the criminal offence committed by the employment agency. It is the aiding and abetting that the union is seeking an injunction to prevent. All the CWU needs to establish is a good, arguable case (and the balance of convenience, to maintain the status quo, would probably mean that Royal Mail was not required to stop using agency workers already on its books, but would not be allowed to recruit more), and an interim injunction would be granted.

Royal Mail is arguing that it is doing no more than recruiting staff to help with the Christmas post and is not recruiting them to fill in for striking workers. In response, the union points out, with some force, that Royal Mail normally engages only 15,000 Christmas staff and it is now trying to recruit 30,000 — and there seems to be no other explanation for the additional numbers. Perhaps Royal Mail’s better argument is that there is a real public interest in post being delivered and this outweighs the inconvenience to the union’s members if an injunction is refused.

Any injunction may prove sterile (which, itself, is an argument against granting one). Even if the CWU prevents Royal Mail from engaging temps through an agency, Royal Mail can still recruit staff directly — for example, through advertisements in local press or via the Jobcentre. It can even recruit staff directly who are introduced by employment agencies (as long as they are not employed by the agency and lent out to Royal Mail). That way, employment agencies are not breaking the law by supplying their own workers to fill in for striking employees, and thus Royal Mail is not aiding and abetting any crime. This is a very neat way of circumventing any injunction.

Moreover, there is a real downside for the CWU if it obtains an injunction — it could expose itself to a multimillion pound bill.

Interim injunctions are granted in a swift procedure where a judge decides whether the CWU has an arguable claim that Royal Mail is (potentially) aiding and abetting a criminal offence and where the balance of convenience lies. A condition of the injunction, though, will be that the union must promise to indemnify Royal Mail against any costs and financial losses if the injunction is later found not to have been justified.

Then, about two months later, another judge looks at it again — each side having now had longer to consider their position and develop their arguments. If the second judge decides the first judge was wrong — and that does happen — he or she will order the CWU to pay all Royal Mail’s lost profits caused by the injunction against using agency staff.

Leaving aside the difficulties of putting a precise figure on the lost profits, it could potentially be a huge liability that the union is exposing itself to by getting an injunction. It’s a high-risk strategy and a step that the CWU cannot be taking lightly.

Daniel Barnett is an employment law barrister at 1 Temple Gardens

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