The former First Minister Carwyn Jones has warned Wales could become an independent country "by accident" in post-Brexit Britain.
Mr Jones told ITV Wales the country risks breaking away from England if the other countries do the same.
"If Northern Ireland voted to join with the south and Scotland left, I don't think England and Wales works.
"It is possible for us to slip into it without having any choice."
He said that a "bad Brexit" would be the catalyst for the breakup of the United Kingdom.
There have been two high profile marches for independence so far this year.
Organisers said they have shown growing momentum and support for Wales to leave the UK.
Yes Cymru has been set up to promote independence in Wales.
Sion Jobbins, who organised the march in Caernarfon described it as "another mass movement for an independent Wales".
He told ITV Wales at the National Eisteddfod in Llanrwst, "there are economic questions - but I don't think this situation is as dark as people think."
MP Guto Bebb said an independent Wales "wouldn't work economically".
"I don't think independence would be good for Wales from an economic perspective.
"When the argument in other parts of the United Kingdom is saying you should do things regardless of the economic impact, then it's very difficult to see how you argue against the emotion of the independence arguments."