Don't count on your mail being delivered over the weekend. Workers are staging further industrial action between today and Tuesday. Londoners will see the worst effects today, with strikes spreading round the country over the following days. In all, an estimated 25,000 workers will potentially walk out over ongoing disputes about perceived erosion of working conditions. Meanwhile, commuters coming in from Essex and East Anglia are far from gruntlement. National Express services into Liverpool Street will be few and far between today thanks to action by the RMT union. Making up the third plank in this fence of discontent are London's firefighters. Members of the Fire Brigades Union are considering action next week following a "sustained period of aggression" by managers.