Jeremy Corbyn has come under renewed pressure to commit Labour to remaining in the single market and customs union after Brexit.
The Labour leader said he wanted to ensure that British firms and universities continued to have “close relationships” with the European Union.
Labour wants a “tariff-free trade relationship” and “a form of customs union”, Mr Corbyn said.
But he was urged to go further and put “clear red water” between his position and prime minister Theresa May’s by backing the UK staying in both the single market and customs union.
Labour MP Chuka Umunna said the party’s supporters could not understand why its official position “continues to cling so closely to that of the Conservative government”.
A commitment to stay in the single market and customs union, which would see only minor post-Brexit change and would maintain free movement of people, could risk alienating Leave-backing voters in some of the party’s heartlands.
Instead the Labour leader said: “What we plan is a tariff-free trade relationship with Europe, a form of customs union, and a trade relationship that guarantees our manufacturing industry and our service industries can continue to trade with Europe and they can continue to trade with us.
“Every major company has very close relationships with Europe. Every university has close relationships with Europe.
“We intend to maintain those relationships and ensure that they are part of our negotiations.
“And that is the case that we have put all the way through the debate in Parliament and we will continue to do so.”
Streatham MP Mr Umunna, a leading supporter of the Open Britain campaign, said: “The overwhelming majority of Labour members and voters want the party to speak out clearly and unambiguously against the government’s plans for a hard and destructive Brexit.
“Labour supporters cannot understand why the party’s official position on Brexit continues to cling so closely to that of the Conservative government.
“For the sake of jobs, prosperity and investment, for strong public services, and for opportunities for the next generation, Labour needs to put clear red water between the party’s position and that of the Conservatives and back British membership of the single market and the customs union.”