The British PM is set to tell MPs that "nothing is agreed until everything is agreed"
Theresa May will hail a "new sense of optimism" in the Brexit negotiations, as she updates MPs in London for the first time since striking a deal with Brussels.
The British Prime Minister will use her speech in the House of Commons on Monday to say she "fully hopes and expects" EU27 leaders to allow talks to progress on to trade.
Cautioning that "nothing is agreed until everything is agreed", she will use Friday's agreement to boost her government's Brexit momentum.
Mrs May is expected to say: "I know that some doubted we would reach this stage.
"I have always been clear that this was never going to be an easy process. It has required give and take for the UK and the EU to move forwards together. And that is what we have done.
"Of course, nothing is agreed until everything is agreed.
"But there is, I believe, a new sense of optimism now in the talks and I fully hope and expect that we will confirm the arrangements I have set out today in the European Council later this week."
She will also tell MPs that moving on to stage two talks will mean the UK can "build the bold new economic and security relationships that can underpin the new deep and special partnership we all want to see".
Yesterday, the UK's Brexit Secretary David Davis faced a backlash for calling the agreement a "statement of intent".
Irish Government Chief Whip Joe McHugh said they viewed the promise of no hard border as binding.
He told RTE's This Week: "We will, as a government, a sovereign government in Ireland, be holding the United Kingdom to account, as will the EU.
"My question to anybody within the British government would be, why would there be an agreement, a set of principled agreements, in order to get to phase two, if they weren't going to be held up? That just sounds bizarre to me."
Remain-backing politicians in the UK are also gearing up for a fight on an amendment to give the British parliament a "meaningful vote" on the full final deal.
Drafted by former Conservative attorney general Dominic Grieve, the proposal would make sure MPs got the final say on an exit package.
Despite the threat, the Mrs May's government has not lost a single vote on amendments to its EU Withdrawal Bill.
Some MPs have withdrawn their proposals after reassurance their issues will be incorporated in other ways or looked at further.