The strike is likely to close about 50 special schools for the foreseeable future and it is also expected to cause disruption in hundreds of mainstream schools.

The walk outs are the culmination of a series of strikes by members of public service union Nipsa who are fighting for the retention of a 32.5 hour week, the current special needs allowance and recognition of NVQ level three.

Special schools across Northern Ireland have already been forced to close their doors for four days as a result of the industrial action.

Tracey Newell, whose son, Conor, attends Knockbreda Primary School in east Belfast, said she believes the Education and Library Boards and Department of Education have failed children with special needs.

Ms Newell said she has not received adequate explanation from either the Department or the Board as to why contingency plans were not implemented.

"If this was mainstream schools we were talking about something would have been done," she said.

"If I didn't send my son to school I would get into trouble, yet when I contacted the Board and asked them whether they had alternative arrangements so that Conor could still go to school they said they had no statutory obligation to provide a contingency plan.

While the classroom assistant who works with her son has returned to work after deciding she could no longer afford to remain on strike, Ms Newell said she has been frustrated by the experience.

"It is the job of the Board and the Department to provide education. In any other business if industrial action was taking place a contingency plan would be put in place. It's good business practice yet the only thing they did was let the schools decide whether they could stay open or not."

As the latest strike action began, NIPSA General Secretary John Corey said members will not accept management's latest offer.

lMeanwhile, mail deliveries across the UK were expected to be crippled after up to 130,000 members of the Communication Workers Union began strike action this morning.