Theresa May has been warned her Brexit could be undone by future generations as key legislation cleared the House of Commons.
MPs approved the European Union (Withdrawal) Bill by 324 votes to 295 - majority 29 - at third reading, with the Government also seeing off a series of proposed amendments during a marathon two-hour voting period.
Brexit Secretary David Davis said the Bill, which transfers European law into UK law, is essential for "preparing the country for the historic milestone" of withdrawing from the EU.
His remarks came after an earlier warning from Tory former Cabinet minister Justine Greening, whose first major intervention since returning to the backbenches saw her claim Brexit will "not be sustainable" if it does not work for young people.
Ms Greening, who left the Cabinet after declining a move from her role as education secretary during Theresa May's recent reshuffle, added that future generations of MPs could seek to "improve or undo" what the current cohort implements.
MPs spent more than 80 hours considering the Bill, including more than 500 amendments and new clauses.
It will appear before the House of Lords by the end of January, where it is expected to receive a rocky ride as it continues its parliamentary journey.
Speaking during the Bill's report stage, Ms Greening (Putney) said: "I represent a very young constituency here in London.
"The bottom line is that, looking ahead, if Brexit doesn't work for young people in our country, in the end it will not be sustainable.
"When they take their place here they will seek to improve or undo what we've done and make it work for them.
"So we do absolutely have a duty in this House to look ahead and ensure that whatever we get is sustainable and works for them."
Asked about Ms Greening's comment, Mrs May's official spokesman said: "The Prime Minister is clear that she is determined to deliver a Brexit which works for all sections of society. Of course that would include young people."
Conservative former chancellor Ken Clarke, speaking in the Commons, claimed future generations risked being made less prosperous if economic barriers were put up between the UK and EU post-Brexit.
He also said: "On whatever basis we come out, there are bound to be adverse effects on the British economy if we create new barriers between ourselves and the biggest free market in the world."
The Government suffered one defeat in the Commons last year over the Bill following a Tory rebellion.
For Labour, shadow Brexit secretary Sir Keir Starmer said the Bill was "not fit for purpose" and insisted there must be a meaningful vote on any deal.
He said: "If the Prime Minister thinks that she can come to this House, put forward her proposed Article 50 deal, and if she loses that vote that she can carry on regardless or walk the UK off a cliff with no deal then she's got another thing coming."
An analysis of the division list for the third reading vote showed four Labour MPs voted with the Government in support.
They were Frank Field (Birkenhead), Kate Hoey (Vauxhall), John Mann (Bassetlaw) and Graham Stringer (Blackley and Broughton).