National Museum of Scotland staff walk out
Staff at the National Museum of Scotland have walked out in a dispute over pay which will be followed by an all-day strike on Friday.
The Public and Commercial Services Union (PCS) said it followed a break-down in talks with museum management.
The union said the museum was being "intransigent" over its decision to remove weekend working allowances. They walked out at 13:30.
It said talks with the management and the Scottish government had failed.
The union said about 100 workers had walked out.
The National Museum of Scotland is the most-visited tourist attraction in Scotland.
Speaking on BBC Scotland's Good Morning Scotland programme, Alex Laurie, PCS branch secretary, said: "Essentially the museum has created a two-tier workforce where anyone employed after 2011 doesn't get paid the weekend working allowance, that was removed from terms and conditions for new starts.
"So it means people are doing the exact same job as their colleagues but for 20% less.
"For low-paid workers this amounts to about £3,000 a year which is quite a significant amount for low paid workers.
"This specifically targeted the low-paid grades within the museum."
Lynn Henderson, PCS Scottish secretary, earlier said: "Museum management and Scottish ministers have proved to be intransigent throughout the process.
"Our members are now forced to take strike action again and have indicated that their resolve remains strong."
A National Museums Scotland spokeswoman, said: "Like many other public sector organisations, National Museums Scotland has had to make a wide range of changes in order to manage the reduced budgets which have been a result of the financial crisis.
"These changes have included reducing staff numbers, reducing a range of budgets, constraining some services and introducing a change to some terms and conditions for staff newly appointed to ensure that we could continue to operate within the funding available.
"National Museums Scotland supports public sector pay policy and delivers the Scottish Living Wage for all its employees. Over recent years, including the period when a public sector pay freeze was in place for the majority of staff, we have differentially increased pay levels for our lowest paid staff."
She added: "Weekend payments are no longer common in the culture and tourism sector across the UK.
"In January 2011, National Museums Scotland introduced revised contracts for new staff who are employed to work weekends; these new contracts do not include weekend working allowances. We explicitly communicate the terms at key stages of recruitment and on appointment.
"No member of staff has received a pay cut following the introduction of new contracts.
"Existing terms and conditions have been preserved for all staff employed prior to 2011."