Some 66 members of the NUT union at Pimlico School struck on Wednesday and Thursday of last week.
The strike was called after the head teacher broke an agreement to restore the lunch break to 45 minutes.
The break had been reduced to 30 minutes last September, but after teachers struck in protest, an agreement was reached to restore it to 45 minutes.
Strikers were angry at the dismissive attitude of the head to the union. On an 80 percent turnout, 72 percent had voted to strike.
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