British Prime Minister Theresa May claims she has agreed with Brussels to create a UK-EU free trade area after Brexit.
She told British MPs the deal would also allow the UK to strike trade deals with other countries from next April.
May said it would stop free movement of people into the UK and end the jurisdiction of the European Court of Justice.
But opposition leader Jeremy Corbyn said the latest deal was 26 pages of “waffle” that pushed Britain towards a blindfold Brexit without any commitments.
"These 26 pages are a testament to the failure of the (Conservatives') bungled negotiations. Nineteen extra pages but nothing has changed," Corbyn said.
"It represents the worst of all worlds: no say over the rules that will continue to apply and no certainty for the future."
Liberal Democrat leader Vince Cable said it had "pathetically weak" parts and was "essentially an agreement to have an agreement".
Others questioned whether any trade deal with the EU would be signed by the end of the transition period.
London and Brussels have already agreed a controversial, draft divorce deal for Britain to leave the bloc.
Both this and the post-Brexit agreement — announced earlier on Thursday — will go before EU leaders at a special summit on Sunday.
"The negotiations are now at a critical moment and all our efforts must be focused on working with our European partners to bring this process to a final conclusion," said May.
They will have to give the green light to the plans before all national parliaments get to vote on the deal.
That includes the British parliament, which is deeply divided on the issue. Some have doubted whether the deal will be approved by UK MPs.
Brexiter MPs in May’s ruling Conservative party — upset with the deal she has brought back from Brussels — are trying to get her ousted from government.