UK must keep EU free movement, says Plaid's Leanne Wood
Britain would have to keep free movement of people in order to stay in the single market, Plaid Cymru's Leanne Wood has said.
But she said there could be room for negotiation with Norway having restrictions on movement.
The party leader told Plaid's conference that the UK should keep free trade with Europe so Wales' economy does not suffer after Brexit.
Leanne Wood said 200,000 Welsh jobs depend on being in the single market.
She called for a Welsh seat at the negotiating table on the terms of leaving the EU, and suggested there was an "opportunity" for new powers and even an independent Wales.
"Plaid Cymru accepts the referendum result," she said.
"Our red line at all times is the Welsh economy", she said, calling for a "soft Brexit".
"Plaid Cymru will never sign off or endorse something that is bad for Wales. We cannot accept that a majority of people in this country would have wanted to do that."
Ms Wood, speaking on BBC Radio Four's Today Programme, said questions of immigration and the single market were "not on the ballot paper" at the EU referendum.
"I've been speaking to a number of key players in the Welsh economy and they're all telling me that tariffs and being outside the EU's regulatory regime would be damaging to them," she said.
When asked if the UK should stay in the single market and keep freedom of movement, she said: "Well I think we'd have to.
"I've been to Brussels and spoke to officials there and they are very clear about the freedom of movement of goods, trade and people all coming as a package."
But she added: "That's not to say there isn't some room for negotiation. Norway have some restrictions on free movement there - you have to have a job before you can go to Norway."
Free movement of people allows citizens of EU countries to live and work across the 28 member states.
'Toxic' debate on immigration
In her keynote speech to delegates in Llangollen on Saturday, Ms Wood outlined a three-point plan to protect Welsh interests when the UK leaves the European Union.
She called for all four UK nations to be involved in negotiations, and claimed people in communities that voted Leave have been "left behind".
Ms Wood accused Prime Minister Theresa May of joining in the "toxic" debate on immigration, refugees and free movement.
"I consider myself to be a Welsh European but I am also a global citizen," she told the conference.
Ms Wood said new powers or a federal UK, all the way to an independent Wales, could be available.
Delegates were told that Plaid Cymru's budget deal with Labour would help Wales but it still needed an alternative government.
"We are not seeking a coalition with the Labour Party," she said.
Analysis by Nick Servini, BBC Wales political editor
Speak to Plaid members in Llangollen at their autumn conference about the departure of the former leader Lord Dafydd Elis-Thomas and Plaid Labour relations at the assembly and you are likely to get different views.
Mention Brexit, and the party has the luxury of being entirely at one.
I say luxury because, having been to both the UK Conservative and Labour conferences, harmony on a Brexit policy can be difficult to come by.
The message time and again from the conference floor has been to warn of the dangers for the Welsh economy of leaving the single market.