The London Brigade has urged people to buy takeaway food during the strike if they had been drinking at Christmas events to reduce the threat of kitchen fires.
FBU members have now taken strike action five times in recent months in protest at changes to pensions and their retirement age, which the union argues threatens older firefighters with losing their jobs or having reduced pensions.
The union said firefighters in their late 50s face the prospect of being sacked or seeing their pension reduced by almost half.
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Kate burst out of the blocks at the London Stadium at the Olympic Park.
Without guarantee, many witnesses had threatened to stay silent by claiming the legal right of privilege against self-incrimination.
The attack happened on a train between St Albans Abbey and Watford North station in November.