Boris Johnson has told the cabinet there is still a “significant amount of work” to do, as UK and EU officials hold talks on getting a deal in place before the 31 October Brexit deadline.
But the prime minister said there was “a way forward” that could “secure all our interests”.
Parliament will meet on Saturday and vote on any deal achieved by Mr Johnson at a Brussels summit this week.
Labour said it would “wait and see” but would oppose anything “damaging”.
Shadow business secretary Rebecca Long-Bailey told BBC One’s Andrew Marr Show: “We don’t think the Tories have moved too far on their deal.”
SNP leader Nicola Sturgeon told the same programme: “We will not vote for the kind of deal specified by Boris Johnson.”
Talks in Brussels between UK and EU officials – described as “intense technical discussions” – are continuing on Sunday.
House of Commons Leader William Rees-Mogg wrote in the Sunday Telegraph: “In the final stages of the Brexit negotiation, compromise will inevitably be needed, something even the staunchest Leavers recognise albeit unwillingly – but as a Leaver Boris can be trusted.”
Ambassadors to the EU from 27 member countries are scheduled to meet this evening and Michel Barnier, the EU’s chief Brexit negotiator, is expected to brief them on the talks.
The summit in Brussels on Thursday and Friday is seen as the final chance to get a Brexit deal agreed ahead of the deadline of 23:00 GMT on 31 October.
A Downing Street spokesperson said: “The prime minister updated cabinet on the current progress being made in ongoing Brexit negotiations, reiterating that a pathway to a deal could be seen but that there is still a significant amount of work to get there and we must remain prepared to leave on 31 October.”
The spokesman said Mr Johnson believed a deal could “respect the Good Friday Agreement”, signed in 1998 in an effort to end the Troubles in Northern Ireland.
It could also “get rid of” the backstop – the plan to prevent the return of a hard border between Northern Ireland and the Irish Republic – which the government says threatens the future of the UK.
Liberal Democrat leader Jo Swinson told Sky News that any agreement reached by Mr Johnson should “be put to the public so they can have the final say”.
But asked whether more MPs would be likely to support a deal, if the Commons first voted in favour of putting it to a referendum, Labour leader Jeremy Corbyn said: “I think many in Parliament, not necessarily Labour MPs – others – might be inclined to support it because they don’t really agree with the deal.
“I would caution them on this.”
Asked about Labour’s stance, Home Secretary Priti Patel replied: “They are clearly playing politics. The British public want to ensure that we get Brexit done.”
Mr Johnson’s revised proposals – designed to avoid concerns about the backstop – were criticised by EU leaders at the start of last week.
However, on Thursday, Mr Johnson and Irish Prime Minister Leo Varadkar held talks and said they could “see a pathway to a possible deal”.
The Benn Act, passed by Parliament last month, requires Mr Johnson to ask EU leaders for a delay to Brexit if a deal has not been reached and agreed to by MPs by 19 October.
The first Queen’s Speech of Mr Johnson’s premiership, delivered during the State Opening of Parliament on Monday, will see the government highlight its priorities, including on Brexit.
Timeline: What’s happening ahead of Brexit deadline?
Monday 14 October – The Commons is due to return, and the government will use the Queen’s Speech to set out its legislative agenda. The speech will then be debated by MPs throughout the week.
Thursday 17 October – Crucial two-day summit of EU leaders begins in Brussels. This is the last such meeting currently scheduled before the Brexit deadline.
Saturday 19 October – Special sitting of Parliament and the date by which the PM must ask the EU for another delay to Brexit under the Benn Act, if no Brexit deal has been approved by Parliament and they have not agreed to the UK leaving with no-deal.
Thursday 31 October – Date by which the UK is due to leave the EU, with or without a withdrawal agreement.