Steve Sinnott, general secretary of the National Union of Teachers, said he was "confident" that teachers would vote in favour of industrial action.

But he called on the Government to reconsider its 2.45% pay offer, with a strike scheduled to go ahead on April 24, subject to the result of a ballot of members.

Speaking as the NUT's annual conference began in Manchester, Mr Sinnott said the union wanted to "speak loudly" and send a strong message to ministers to protect teachers' pay.

"Hopefully, if the Government is listening they will take action to prevent the sapping of teachers' morale and the recruitment and retention crisis that will come from real-terms cuts in teachers' pay," he said.

"I remain confident that we will have a positive ballot in favour of action.

"I can't say for certain, but just from speaking to teachers as I have gone round schools and NUT meetings, it looks pretty positive."

The Government has announced a 2.45% pay rise for teachers in England and Wales this year, with further rises of 2.3% in 2009 and 2010.

A spokeswoman for the Department for Children said: "Strike action can only achieve one thing - disruption to children's learning."

She said the pay offer was recommended by an independent body, adding that the rise for teachers was "both fair and responsible in the current economic climate".