The Education Secretary, David Blunkett, has accused teachers who take action over staff shortages of "abandoning" schoolchildren and damaging their prospects.

One union leader retorted that Mr Blunkett's "emotional claptrap" did not deal with the problems teachers were facing.

If you walk out on a class and send the kids home you damage their life chances

Education Secretary, David Blunkett

The row came as the government was giving some details of new measures intended to boost short-term recruitment into teaching to cope with the shortages in some schools.

There is a possibility that pupils could soon be sent home soon as the two main teachers' unions in England, the National Union of Teachers (NUT) and the National Association of Schoolmasters Union of Women Teachers (NASUWT), begin action this week following ballots in Greater London and in Doncaster.

Teachers will refuse to cover for vacancies and absences beyond three days and will not accept changes to timetables caused by a school's inability to recruit sufficient teachers.

Mr Blunkett told the Daily Mail: "Far from being intimidated, we are getting increasingly iron-souled about this and we are looking at ways we can deal with the unions in a way they could be surprised about."

'Teachers will cover'

In radio and television interviews he has declined to elaborate on what this meant.

We're not going to be put off by emotional claptrap on the part of the education secretary

Union leader Nigel de Gruchy

"We have two of the unions, representing a small number in the particular schools we're talking about, threatening to walk out on children," he said on BBC Radio 4.

"We have a lot of teachers who are prepared to cover on the basis that they know we're taking action."

More teachers were in training - 2,250 would be coming into schools in September.

"We need to take both positive action as we are doing today to get returners into the classroom and we need to say to the unions that if they actually abandon children - because that's what it is, if you walk out on a class and send the kids home you damage their life chances."

He added: "I don't want to downplay it because there is a problem."

But it was "partly a problem of success", with smaller infant class sizes and extra booster classes to help children with this summer's exams.

'Emotional claptrap'

Mr de Gruchy said that if teachers were recruited - from Canada or wherever - then that met the demands of the unions' action and proved it had been necessary to shake the government out of its "extraordinary complacency".

But it was a waste of public money to come up with short-term solutions if they did nothing to address the underlying issues which had driven people out of teaching in the first place, he said on BBC News 24.

The education secretary's "tough talk" had appeared only in one newspaper and he seemed more concerned with impressing Daily Mail readers than solving teachers' problems.

"We're not going to be put off by emotional claptrap on the part of the education secretary," he said.

"We're going to keep our eye on the ball. The central issue is how do you make teaching a much more attractive profession?

"The government has started to do something. It's too little too late. The government has done nothing to improve the conditions in which teachers operate and that's the fundamental problem."

'Upping the ante'

Mr Blunkett later told the network that he was anxious to stress all the steps the government was taking to recruit and retain teachers and to put more money into schools.

His message to the unions was: "OK you are running up to the teacher conferences at Easter, you are taking advantage of any potential general election to up the ante - but the ante is being upped on children not on us as a government."

He said he would be monitoring whether they "overstep the mark in terms of simply abandoning classes".

The NUT members' action began on Monday while the NASUWT's starts on Tuesday.

The action follows a ballot of union members in Doncaster and Greater London.

"This action will only bite in those schools where there's a problem with shortages," a spokeswoman for the NUT said.

Both unions are holding other ballots in other parts of the country, which could see the action spreading into many more schools.