Theresa May’s speech on Brexit in Italy on Friday will represent an “open and generous offer” to the rest of the EU, a cabinet minister has told the BBC.
It is thought that might include a guarantee that no EU country would lose out from changes to the EU’s current budget as a result of the UK leaving.
But another minister warned against offering too much money, saying “it’s our only leverage”.
Mrs May is briefing her cabinet on Thursday morning about the speech.
The event in Florence is being seen as an attempt to break the deadlock on the negotiations, with the EU unhappy at the lack of progress on agreeing the UK’s “divorce bill” from Brussels.
The cabinet meeting comes amid reports of ministerial splits over Brexit.
Foreign Secretary Boris Johnson was accused of undermining the PM with a 4,000-word article about Brexit.
He subsequently denied reports he planned to resign if his blueprint was not followed and described the government as “a nest of singing birds”.
The foreign secretary and prime minister travelled back from the United Nations in New York on the same flight on Wednesday night.
Debate ahead of the speech has focused on the detail of the time-limited transition period after Brexit, how much the UK will pay as it leaves, and whether it will continue contributing to EU budgets in years to come.
So far, the government has said the UK will honour its commitments but that the days of “giving huge sums of money” are over.
Downing Street has also described as “speculation” a Financial Times report that chief Brexit “sherpa” Olly Robbins, who reports directly to Mrs May, had told Germany she will offer to pay £20bn in the period up to 2020 to cover gaps in the budget left by the UK’s departure.
The fourth round of Brexit negotiations begins on 25 September, with the UK due to leave the EU in March 2019.
Analysis – By BBC Political Editor Laura Kuenssberg
We are one of the biggest contributors to the EU pot, so leaving dents the planned financial arrangements if we just go and take our cheque book with us.
If that is the promise that is roughly to the tune of £20bn, although it would be surprising if Theresa May named a figure herself – it’s not her style and any actual numbers will be subject to far-off negotiations.
But in terms of the bill, that could just be the start of it. Plugging the hole in the current budget doesn’t deal with what the EU sees as our long-term obligations – whether that’s diplomats’ pensions or our share of money that’s been loaned to other countries.
Read Laura’s full blog
The UK is keen to intensify their pace and open discussions on the country’s future relationship with the EU, including trade, as soon as possible.
But this cannot happen until the EU deems sufficient progress has been made on the initial subjects being discussed, including the UK’s financial settlement.
The two sides are also trying to reach agreement on the status of UK and EU expats after Brexit, and the impact of Brexit on the Northern Ireland border.
The pro-European Liberal Democrats called on Mrs May to clamp down on Cabinet dissent by sacking Boris Johnson and to use her Florence speech to “drop her reckless insistence that no deal is better than a bad deal”.
The party’s Brexit spokesman Tom Brake said: “This a chance for the prime minister to show she’s listened to the message sent by voters at the election and to seek a Brexit deal that has majority support in the country.
“That should include staying in the single market, separating the issue of EU nationals’ rights so they are not used as bargaining chips, and giving the public a vote on the final deal.”