Thousands of civilian police staff - including 999 call handlers - are set to strike on New Year's Eve, the PCS union has said.
The planned strike would coincide with a walkout by London firefighters and could see around 7,500 civilian workers taking action on one of the busiest days of the year.
The strike was planned after a 1% pay rise was imposed by the Metropolitan Police last month, which is below inflation.
Police community support officers, 999 call handlers, detention officers in custody suites, and a range of administration and professional support staff are among those due to take action.
The Met said they were "confident" they have good contingency plans in place in the event of a strike.
More top news
Fourteen police officers were injured in protests over death of Edir Da Costa, the Met has confirmed.
A full list of buildings that have failed fire safety checks in London has been confirmed following the tragedy of the Grenfell Tower fire.
One of the youngest victims of the Grenfell Tower tragedy choked to death on fumes from the fire, an inquest heard.