A year filled with industrial action is set to end with strikes by security guards and railway cleaners over payment disputes.
Around 300 members of the Public and Commercial Services (PCS) union, who provide security at the Palace of Westminster, are set to strike on New Year's Eve.
This will mark their fourth day of industrial action this year, as they continue to dispute pay, and terms and conditions.
PCS general secretary Fran Heathcote said: "The employer has reduced members' annual leave and incorrectly claimed that staff had agreed to it.
"The recent cash offer put to workers is nothing short of an insult."
Cleaning staff on the Docklands Light Railway (DLR) will also strike on New Year's Eve in a separate dispute over pay.
Eddie Dempsey, general secretary of the Rail, Maritime and Transport (RMT) union, said: "Cleaning staff on the DLR do a vital job keeping London's transport network safe, clean, and presentable.
"Transport for London, which oversees outsourcing contracts, must bring these services back in house and pay workers proper sick pay, if we are to avoid these kinds of disruptions in 2026."
It adds to the persistent wave of strike action that has unfolded despite the Labour government's efforts throughout the year to mend industrial relations, following a period marked by extensive strikes under the previous Conservative government.
Among the long-running disputes that have characterised 2025 are those involving resident doctors, Birmingham refuse collectors, and drivers on Hull Trains.