Striking staff at the National Museum of Scotland – who are not paid extra to work weekends – claim they are having to find part-time jobs to make ends meet.
Around 120 employees at the attraction walked out on Monday, as the Public and Commercial Services (PCS) wants management to reverse its decision to remove a weekend working allowance for staff that joined the company after 2010.
The museum was the most visited free attraction in the country last year with more than 1.6 million visitors, and was also the busiest museum outside of London.
Currently, employees who joined the company before December 2010 are being given an additional allowance for working weekends.
Alison Johnstone, Scottish Green MSP for Lothian, met members of the union and said that more needed to be done to ensure equality in the workplace.
She said: “Museum staff not receiving the weekend working allowance tell me they feel under pressure to find extra work to make ends meet. It’s unacceptable.
“People are looking for something flexible to fit in with their hours at the museum but the preferred and easier option would just be to get the same weekend allowance as everyone else.
“This museum is one of the Scotland’s crown jewels and this ongoing dispute has caused a very important building to be closed during the Fringe – it’s very important to both education and tourism.”
The weekend working allowance debate has been an ongoing dispute for 18 months.
PCS Scotland said employees who get the allowance earn on average £2000 or £3000 more a year than an employee who joined from 2011 onwards.
Ms Johnstone added: “The current situation is having a clear impact on morale at the museum.
“The staff in this workplace show support for one another and even those who are not affected by this problem want it fixed.
“Imagine working alongside someone who is being paid more than you are for doing exactly the same job.
“This museum is an important asset for Edinburgh and Scotland and its workers deserve better treatment.”
A spokeswoman for the National Museum of Scotland said: “Weekend payments are no longer common in the culture and tourism sector across the UK.
“In 2011, in response to the financial crisis, we introduced revised contracts for new staff which do not include weekend working allowances.
“No member of staff has received a pay cut following the introduction of new contracts in January 2011.
“National Museums Scotland supports public sector pay policy and delivers the Scottish Living Wage for all its employees.”