Teachers have vowed to campaign with other unions across Britain against the government’s plans to raise the retirement age to 65. delegates dismissed a left-wing call for a ballot on separate industrial action by 152-123.

Michael Dolan, West Dunbartonshire, said the plans affected all teachers who had not reached the age of 50 by September 2003.

Members who wanted to leave at 60 would face huge losses in benefit because of the financial penalties imposed.

He estimated that a teacher aged 50 would have to build an extra pension pot of around pound;80,000 in ten years, which would mean a “staggering” pound;400 off the take-home pay of someone at the top of the unpromoted scale, or a pay cut of 23 per cent.

“The alternative is to work longer, reduce life expectancy, create many intolerable pressures on many ageing teachers and detrimental effects on the education of their children,” he said.

Andrew Fullwood, South Lanarkshire, said “five years on working life is death” while Ewen Macleod, East Ayrshire, said 40 years’ service was unrealistic for most teachers. As many as 40 per cent of teachers retiring last year did so before reaching the current retirement age.