A second EU referendum will not solve the problem of divisive politics, ex-Plaid Cymru leader Leanne Wood said.
The Rhondda AM supports another poll on the final Brexit deal, but warned the results would not be "conclusive".
Her successor Adam Price wants another referendum in an attempt to reverse Wales and the UK's decision in 2016 to leave the European Union.
Prime Minister Boris Johnson said the UK would leave on 31 October with or without a deal.
The new PM said he would prefer to get a deal with the EU, but he recognised this "may not happen".
Theresa May's Brexit deal was rejected three times by MPs - with many concerned over the Irish border backstop plan.
Mr Johnson has urged the EU to make changes to the deal but it has repeatedly said the withdrawal agreement cannot be renegotiated.
'Concern about democracy'
Leaving without a deal has been met with fierce opposition from other parties and there have been calls for a second referendum, including Plaid.
Asked if it was the right policy direction for the party, Ms Wood said: "I don't think you can sit on the fence."
She said she still had concerns "about the democratic implications of another vote" despite telling the party conference as leader two years ago she could back another Brexit referendum if there was no deal with the EU.
Ms Wood told BBC Radio Wales' Sunday Supplement programme: "I don't think that we should just embark upon these questions lightly because people will rightly ask what is the point of voting again in any future referendum or indeed election.
"So, there is a real concern about democracy but also there's a concern about democracy if we do crash out of the European Union and it's not just a concern for democracy, it's also a concern for the economy, for the future for young people, for a whole raft of economic issues."
She said a focus on the Brexit debate meant "we just simply can't get other questions on to the agenda".
"The fact that the homelessness problem is reaching crisis point, the fact that we are feeding needy families here in the Rhondda by trying to run an elimination of food waste scheme but the demand is huge.
"These are very real problems that are not getting the air time that they deserve because all of the air time, all of the energy, all of the resources are being spent on trying to solve this Brexit problem," she added.
You can listen to BBC Radio Wales' Sunday Supplement programme at 8am or download the podcast on BBC Sounds.