Bank of England workers are to stage a four-day strike in a dispute over pay.
Members of the Unite union will walk out from July 31, the first strike at the bank in more than 50 years.
The announcement follows a 95% vote in favour of industrial action.
Unite members working in the maintenance, parlours and security departments will be taking strike action on July 31, August 1, 2 and 3.
The union warned that if the bank fails to resolve the pay row it will be consulting its members across other departments as part of a plan to escalate the dispute.
Unite said staff were angry they have been given a below inflation pay offer for the second year running, while up to a third will get no pay rise in 2017.
Unite regional officer Mercedes Sanchez said: “Staff at the Bank of England have made their anger clear by voting for strike action due to their employer’s outright refusal to negotiate a fair pay deal for its workforce.
“The result of the bank’s unwillingness to negotiate fair pay will be that the bank’s sites, including the iconic Threadneedle Street in the city of London will effectively be inoperable without the maintenance, parlours and security staff.”
Unite said the dispute has been caused by the imposition of a 1% increase in the pay “pot” for the year from March. The amount an individual will receive is at the discretion of line managers, so that employees could receive less than 1% and some will receive no rise at all, said the union.
A Bank of England spokeswoman said: “The Bank has been informed of industrial action being called by Unite the union. The union balloted approximately 2% of the workforce.
“Should the strike go ahead, the Bank has plans in place so that all sites can continue to operate effectively. We will continue to have discussions with Unite and hope that there will be a positive outcome.”