The Charity Retail Association, a body which represents organisations all over Wales, are urging AM's to consider the detrimental effect that will be caused if they implement a series of recommendations into how charities pay their business rates.
The Welsh Government are currently considering proposals put forward following a review into business rates carried out by Prof Brian Morgan.
The review proposed the following situations should be put out to consultation:
Limiting rate relief to 50 per cent for 'larger charity shops trading in new goods.
Placing an upper Rateable Value rate on the definition of premises eligible for charitable rate relief.
Introducing tighter eligibility criteria for claiming rate relief.
Limiting the number of premises eligible for charitable relief in a town center or limiting relief to one per charity in a given area.
Prof Morgan is due to report back to the Assembly Government before Christmas but the Charity Retail Association believe any changes would have severe effects of the estimated 700 jobs and 9000 volunteering opportunities charity shops currently offer.
Oxfam Cymru runs 27 retail shops across Wales and Advocacy Officer Lila Haines believes there's more at stake from the Business Rates Wales Review than people perhaps realise.
"Our charity shops are so much more than just retail outlets. As well as offering affordable clothing in a sustainable way, there is a social aspect that is vitally important to Wales' communities.
"If the Welsh Government takes these recommendations forward, not only would our projects be at risk but it could well mean the closure of some of our stores, which will have a hugely negative impact on so many community groups across Wales".
A Welsh Government spokesperson said: "The Minister for Business, Enterprise, Technology and Science is sensitive to the many viewpoints on the issue of business rates relief for charities.
"Therefore, she has asked Professor Morgan and Juliet Luporini, from the Business Rates Task and Finish Group to examine this issue further by seeking the views of charities, business and others.
"They will also look at whether reliefs could meaningfully support social enterprises and credit unions. A call for evidence has been launched and we would encourage as many people as possible to take part."