Thousands of teachers were handed redundancy notices last week as education authorities scrambled to reduce costs.

Draconian cuts have been sparked by the worst education funding crisis since World War II. It led teachers in Portland, Oregon, to agree to work free for two weeks a year - an unparalleled gesture.

By forgoing their salary for 10 days, Portland’s 3,300 teachers stand to lose $1,000 (pound;624) to $4,000 in pay, but the wage cut has averted the loss of 24 days from the school year, the education authority’s only other option.

A few months ago schools were falling over themselves to recruit thousands of extra staff to cope with bulging pupil rolls and bolster the ageing workforce. But now it is a case of last in, first out.

Teachers in California, where education spending is to be slashed by $5.4 billion because of the state’s record $34.6bn deficit, were hardest hit.

Education chiefs in Oakland which is facing cuts of $171 million outlined plans to lose one in five of the city’s 2,700 teachers. Almost 1,200 and 840 staff in San Diego and Fresno, respectively, may be laid off.

US staff are typically entitled to five months’ notice. Those affected may yet get a reprieve if the crisis abates, but that is unlikely with the only prospect of relief - a big rise in local taxes - politically untenable at the moment.

Californian education authorities are also considering mass school closures to make ends meet. Vacaville, near San Francisco, has already decided to board up two schools to save $7.2m.

Schools officials in Illinois - where education authorities have already started wielding the axe - said last week that redundancies there could run into “thousands”.

An announcement that 850 teachers would be dismissed to pare costs in the Chicago suburb of Elgin prompted gallows humour. Staff at Abbot middle school turned up for work sporting pink clothing - a humorous poke at the customary colour of US redundancy notices.

Class sizes could balloon to 37 if the layoffs take effect, local teachers estimated. They already have their work cut out teaching an average of 25 pupils per class - less than half Elgin’s secondary school students met academic proficiency standards last year.