defence secretary michael fallon led a ferocious assault on the labour leader .
claiming he is a ` backstabber ' who can not be trusted not to sell out in a ` grubby ' in favour of unilateral disarmament , i 'm not in favour of unilateral disarmament .
` we 're going to see whether there 's any way you could do it with three -lsb- submarines -rsb- that