Hundreds of security staff based in the Houses of Parliament are taking strike action in a dispute over pay and conditions.

Public and Commercial Services (PCS) members who work at the Palace of Westminster will walk out between 07:00 BST and 19:00 on each of the next two Wednesdays and Thursdays.

The union says its employer’s removal of six days’ annual leave from members’ contracts, pay stagnation and a widening ethnicity pay gap has made them “particularly angry”.

A UK Parliament spokesperson said: “The decision to proceed with strike action is a disappointing outcome, following months of continued engagement to try to resolve outstanding concerns.”

During the action, members of the public with tickets to Prime Minister’s Questions will be unable to enter the building and Parliamentary pass holders will not be allowed to bring guests on to the estate.

The union will also carry out action short of a strike, including an overtime ban and a work-to-rule, until 12 September.

PCS general secretary Fran Heathcote said: “To fight for fair pay and conditions, our dedicated members at the Palace of Westminster will take industrial action this week just as parliament returns from recess.

“Day and night, they work incredibly hard to ensure the safety of MPs, Lords, staff and visitors in the UK’s national parliament building.

“They deserve to be treated fairly and to have their many concerns addressed by the employer.”

A UK Parliament spokesperson said: “Parliamentary security staff are valued colleagues.

“We remain committed to working closely with staff and unions to address the issues raised and to reach a resolution.

“As always, the safety and security of all members of the Parliamentary community, as well as those that visit Parliament, remains our absolute priority.

“Working closely with the Met Police, we have implemented robust contingency plans which will ensure both the safety of the estate as usual and no disruption to parliamentary business.”