Many more days are lost to strike action in public sector industries than in the private sector according to data available here

Labour Market: Labour disputes, UK from Timetric

Public sector industries include London Underground, the civil service, the fire service and the national health service. The spikes in days lost arising from industrial action reflect the volume of workers affected when industrial action is taken. There are plenty of trade union - employer disputes in the private sector (for example the recent clash between British Airways and UNITE representing cabin crew) but these disputes rarely lead to enormous losses in days worked.

In the summer of 2011 there is the prospect of hundreds of thousands of workers taking selective action over the issue of public sector pensions reforms - several teaching unions are now balloting their members ahead of strike action.