As thousands marched, the war of words between the unions and government continued. It claimed the vast majority of workers didn't vote for the action.
The Labour Leader and Doncaster North MP Ed Miliband said the strikes were wrong when negotiations were continuing.
Our Political Correspondent Paul Brand has been gauging reaction at Westminster.
Almost 600 schools have been closed across the region as teachers join a public sector strike.
Teachers across the Yorkshire and Lincolnshire will be out on strike on Thursday 10th July. Click here to see if your school is closed