Despite a frisson of strike action in recent weeks, the number of work stoppages and overall number of picketers has been gradually decreasing.

Statistics from the Ministry for Business, Innovation and Employment show that the number of employees involved in strike actions in 2005 was almost 18,000, but in 2016 this dropped to just 430, and last year 421.

Unite Union's national secretary Gerard Hehir said this trend reflected the increasing rate of members that were retiring.