The Charity Retail Association will hold an "emergency summit" with opposition Welsh Assembly members to discuss proposals to cut business rate relief for charity shops in Wales.
The meeting will take place on 19 June at the National Assembly for Wales in Cardiff.
Assembly members Nick Ramsay, shadow business minister for the Welsh Conservatives, Eluned Parrot, a Liberal Democrat, and Alun Ffred Jones, a Plaid Cymru member, will attend the meeting. Parrot and Jones are both members of the Welsh Assembly’s business and enterprise committee.
The meeting comes after the Welsh government unveiled proposals to reduce the business rate relief for charity shops in Wales from 80 per cent to 50 per cent from 2022. A consultation on the proposal runs until 28 June.
It is one of 10 recommendations made in a report on charity business rate relief in Wales by Brian Morgan, professor of entrepreneurship at Cardiff Metropolitan University.
Wendy Mitchell, head of policy and public affairs at the CRA, said Edwina Hart, the Welsh business minister, had declined the association’s invitation to attend the meeting.
Graham Benfield, chief executive of the Wales Council for Voluntary Action, will attend. Charities will be able to raise their concerns directly with the members.
The CRA said it had significant concerns about the evidence on which the recommendations are based and questioned the assumption that charity shops are responsible for high-street decline.
Warren Alexander, chief executive of the CRA, has said the proposals would be a "new tax on charities" and could "seriously damage" charities in Wales if they were adopted.