Striking workers want their employers to enter back into negotiations over their "measly" pay rises with unions, a GMB representative told Good Morning Britain.
Regional Representative Joe Morgan was also critical of proposed changes to the number of votes needed before a strike could be held, saying if the same rules were applied to Parliament, "you wouldn't have one MP elected across the country."
Union leaders said they were "overwhelmed" by support after a strike by public sector workers caused widespread disruption.
David Cameron, Michael Gove and other Government figures depicted in a variety of unflattering manners by striking public sector workers.
Hundreds of schools are to close tomorrow as teachers join strike action. Find out what schools in your area are affected.