Workers at the Bank of England will stage a four-day strike starting on July 31 in support of a pay claim.
According to the Unite union, the strike will leave its headquarters in the City of London without security and maintenance staff and “effectively inoperable”.
However, the Bank says it has contingency plans in place.
It will be the first time in more than 50 years that the Bank has faced a walkout by staff.
The Bank of England has 4,000 staff, but it is unclear how many of them will walk out at the end of this month.
The move follows a ballot which produced a 95 percent vote for strike action.
The union said its members were angry that, for the second year in a row, they had been offered a pay rise that was below the rate of inflation.
This year’s pay rise was capped at one percent, with up to one-third of staff due to get no pay increase at all this year, the union said.
In a statement, the Bank of England said: “The Bank has been informed of industrial action being called by Unite the union.
“The union balloted approximately two percent 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.”
The union said it was prepared to escalate the dispute if Bank chiefs failed to settle the pay row.
“The result of the Bank’s unwillingness to negotiate fair pay will be that the Bank’s sites, including the iconic Thread needle Street in the City of London, will effectively be inoperable without the maintenance, parlours and security staff,” said Unite regional officer Mercedes Sanchez.
The parlours department welcomes guests to the bank and makes arrangements for refreshments.