AMSTERDAM (Reuters) - Dutch teachers and lecturers at all levels will hold their first ever joint strike on March 15 to press demands for wage hikes and better working conditions, labor unions said on Wednesday.

FILE PHOTO: Dutch primary school teachers rally during a strike to press demands for higher wages, in The Hague, Netherlands, October 5, 2017. REUTERS/Cris Toala Olivares/File Photo

The looming walkout reflects growing frustration across the workforce in the Netherlands, with employees in many sectors feeling left behind by strong economic growth that has not been matched by wage increases.

The March 15 stoppage is expected to shut schools and universities, and follows similar walkouts by primary school teachers in October and December 2017.

“Basically every teacher, at every level, says the workload is too high,” spokeswoman Simone van Geest of teachers union AOB said. “There is a huge shortage of teachers at both primary and secondary level and wages are simply too low.”

The teachers are calling for an increase of 4 billion euros ($4.6 billion) to the government’s annual 30-billion-euro education budget, with over half of the extra money going to primary and secondary schools.

For wage rises, the unions are seeking 1.1 billion euros this year, increasing to almost 2 billion in 2022.

Primary and secondary school teachers currently earn 2,500-4,000 euros per month before taxes.

“We have announced this strike early to give teachers, schools and pupils ample time to organize,” Van Geest said. “We don’t expect the government to come up with a last-minute effort to prevent it.”

In response, Michiel Hendrikx, spokesman for the Education Ministry in the centre-right governing coalition, said the education sector was “already the recipient of the largest part of this government’s extra investments”.He declined specific comment on the strike warning.

In 2017, the Dutch government promised primary schools 700 million euros in extra funds through 2021, though teachers at the time already said they needed double that amount to cover wage increases and pay for extra classroom assistance.

Primary school teachers continued a series of smaller work stoppages last year, joined by university staff in September, who demand more than 1 billion euros in extra investment to improve their working conditions.

The Netherlands has been one of Europe’s top economic performers, with growth hitting decade-highs of around 3 percent in the last two years, but real disposable incomes have hardly budged since the turn of the century.