Paris - A strike by unions representing teachers, secondary school students and public sector workers is expected to shut French schools and greatly reduce other public services Thursday.

The schools job action was called by nine unions representing public and private school teachers, as well as by five student unions, to protest plans by the government of President Nicolas Sarkozy to cut some 11,200 teaching jobs this year.

In addition, French postal workers, hospital employees, customs officials and local and national civil servants are expected to walk off their jobs in large numbers, creating what many fear may become a "black Thursday" in France.

While public transport and the national railway service will likely be unaffected by the job action, delays are expected at some airports, as a small number of air traffic controllers may join the strike.

Large street demonstrations in cities throughout France have been set to accompany the strikes in what is widely seen as an important face-off between the government and France's traditionally powerful and stubbornly defiant trade unions.

Education Minister Xavier Darcos has said repeatedly that the strikes and demonstrations will not deter him from carrying out reforms to make the country's education system more efficient, and he has threatened to enact laws that would make it mandatory to keep schools open during strikes.

On Thursday, only about one in 10 French communities is expected to provide a "minimum service" in their schools and open doors to students who wish to attend class.

Public sector workers are protesting government plans to reduce posts by not replacing retiring civil servants. Unions estimate that this could slash 30,000 to 40,000 posts a year from the state payrolls.

Trade union officials have threatened to carry the movement into the fall if the government does not respond to their demands.

However, Sarkozy and his ministers have repeatedly said the reforms were necessary for France to meet the European Union's budget deficit threshold of 3 per cent of GDP.

Sarkozy has already ruffled feathers in Brussels by saying that France would be unable to balance its budget until 2012, two years after the EU's "medium-term objective" (MTO) date. (dpa)