Jeremy Corbyn has hit back at Labour critics calling for the UK to stay in the single market after Brexit.
The Labour leader insisted that remaining in the trading arrangement was dependent on being in the EU.
The comments came after some Labour figures called for the party to change tack and campaign to remain in the single market and customs union after withdrawal.
Mr Corbyn told ITV's Peston on Sunday: "The single market is dependent on membership of the European Union.
"Do we have a trading relationship with Europe which is tariff free, which is based on access to that market, and access of Europe to our market? Yes.
"Do we push for that in the negotiations? Yes. Is that what we have said to the European Union in opposition? Yes.
"You have to make a special relationship with the European Union."
Mr Corbyn said that he was not calling for a second referendum.
"We are not supporting or calling for a second referendum. What we have called for is a meaningful vote in Parliament."
However, Mr Corbyn sidestepped the question of whether Labour could support a new referendum in the future.
Mr Corbyn said Labour would vote against landmark Brexit legislation which returns to the Commons in the next few days unless its concerns were met.
"We have got the vote coming up this week on the EU (Withdrawal) Bill. We have set down our lines on that which are about democratic accountability.
"They are about protection of workers, environment and consumer rights. And are about human rights across Europe, such as the charter of fundamental rights, as well as the European Court of Human Rights.
"If our tests are not met by the Government then we will vote against the Bill."
Mr Corbyn expressed concern about some parts of the single market set-up.
"There are also aspects of the single market one wants to think about such as the restrictions on state aid to industry, which is something that I would wish to challenge."
Asked about a second referendum on any Brexit deal, shadow foreign secretary Emily Thornberry told BBC1's Andrew Marr Show: "If 90% of the population was now saying we must stay in the European Union and we must not leave then that would be a challenge that would be there for all of us who are democrats.
"But, at the moment, and as things currently stand, we proceed in good faith, we do as we are instructed and we are leaving the European Union.
"We have said that we must respect the result of the referendum which means that we have to leave, but we have to look after the economy which, in my view, means that we don't go very far."
Deputy Tory party chairman James Cleverly said: "Once again the very top of Labour, this time Jeremy Corbyn and Emily Thornberry, have failed to rule out a second referendum.
"Every step of the way Labour are trying to frustrate the Brexit process rather than make a success of it.
"Only the Conservatives are working to ensure that when the UK leaves the EU we take back control of our laws, money and borders - Labour just can't be trusted to deliver on leaving the European Union."