Public sector strikes were at a record high in 2011 with 1.4 million working days lost to strikes.
This amount is the highest since 1990. The number of days of industrial action were boosted by the one-day strike by public sector workers in November against Government changes to pensions.
Over 1.5 million workers took part in strikes last year, almost 12 times the number in 2010. Most of the strikes involved pay, and just over half lasted a day.
See more figures concerning strike action on Public Sector Executive.