P is for People campaign for public toilets at Senedd
Campaigners have protested outside the Senedd in Cardiff Bay to urge the Welsh government to keep public toilets open.
The P is for People campaign, run by the Welsh Senate of Older People, said public toilets were a lifeline.
Its members claimed that without them people could become "prisoners in their own homes" because they are afraid to go out.
The Welsh government said provision and maintenance of toilet facilities was a matter for local authorities.
The Welsh Senate of Older People consists of 57 organisations representing older people, and campaigners from around Wales gathered on the steps of the assembly on Wednesday to urge ministers and local councils to work together to save toilets.
'Rate of knots'
One, Phyllis Preece, said the senate wanted to "send a clear message that the public toilet network around Wales must be saved".
"Public toilets are a lifeline, especially for older people, pregnant women and parents with young children, yet they seem to be disappearing at a rate of knots from our communities," she said.
"The P is for People campaign has bought people from around the country together at the Welsh assembly to demonstrate the strength of feeling that there is about saving our public toilets.
"People can become prisoners in their own homes because they are afraid to go outside because there are no public toilets where they live," added Mrs Preece.
"Unless there is action from the Welsh government to make it law that local authorities must provide public toilets, we worry that public toilets will become a thing of the past."
The senate said the Welsh government needed to address the fact there is no statutory duty on local authorities to provide public toilets.
A Welsh government spokesman said: "The provision and maintenance of toilet facilities is a matter for local authorities, taking account of local needs and priorities.
"We have no plans to make this a statutory duty."
The spokesman said £107,000 had recently been paid to local authorities towards a scheme which allows councils to pay up to £500 to local businesses which allow the public to use their toilets for free.
Only Newport, Flintshire, Rhondda Cynon Taf and Torfaen have not signed up to the scheme.
According to the Welsh Senate of Older People, the British Toilet Association estimates that the number of UK public toilets has declined by more than 40% in the last decade.
Earlier this year, BBC Wales found there are now about 200 fewer traditional public toilets, compared to the late 1990s.
Public toilet provision varies hugely across Wales.
Gwynedd, for example, has 86 traditional public toilets, as well as 36 premises offering use of their loos under the government scheme.
However, Torfaen, a much smaller local authority, has just seven conveniences and has not signed up to the scheme, although it said people could use facilities in its public buildings.