BIG Pit in Blaenavon will be closed this weekend as workers go on strike at museums in Wales.

Members of the Public and Commercial Services (PCS) union at National Museum Wales have, in a ballot that closed on July 21, backed action in opposition to plans to scrap premium payments for weekend working, which make up as much as 15% of the take-home pay of front-of-house staff.

This Saturday will see industrial action taken that will affect seven National Museums Wales sites.

Big Pit National Coal Museum in Blaenavon, along with the National Waterfront Museum, Swansea; the National Slate Museum, Llanberis; the National Wool Museum, Dre-fach Felindre will be closed all day on Saturday, August 1.

Big Pit will also be closed on Sunday, August 2, while The National Roman Legion Museum in Caerleon will be unaffected.

St Fagans National History Museum and National Museum Cardiff will be open on Saturday, but with limited services.

A spokeswoman for National Museums Wales said: “We apologise for any inconvenience this may cause.

“We are very disappointed that PCS has taken the decision to go ahead with industrial action despite us entering into a process of conciliation with them via ACAS, which is ongoing.”

National Museum Wales has proposed to increase the basic pay of its lowest paid staff by 4% during the next financial year in addition to the 4% increase those staff members have received since 2011, also to introduce the Living Wage of £7.85 an hour to mitigate the impact on its staff.

She added: “We have suffered a reduction of over 20% in our revenue budget over the last four years, and following the most recent announcement from the Westminster Government, things are not likely to get any easier in the near future.”

The union explained the payments go to staff who are contracted to work rotas- around half of the museums’ employees- are paid £54.24 extra per day on top of their salary for working Sundays and bank holidays, and £30.06 extra for working Saturdays.

Neil Harrison, PCS branch chairman at National Museum Wales, said: "We appreciate that their budget has been cut and they have to make savings but we have put forward alternative proposals, which they have rejected.

“We do not believe that staff who are already on very modest wages should take such a big hit, especially when senior management's own salaries do not face a comparable cut.”