There were claims Mrs May had secured a secret deal with the EU. "Still necessary to repeat this, it seems", she said.
The report claims an "all-UK customs deal" will be written into the legally binding withdrawal agreement, which would do away with the need for the controversial "backstop" arrangement agreed by the United Kingdom last December, which would see Northern Ireland remain in full alignment with the EU's single market and customs union rules in the event of a no-deal Brexit.
Irish Foreign Minister Simon Coveney has insisted that a time-limited Brexit backstop will never be agreed by the Irish Government or the EU.
"These ideas are not backstops at all and don't deliver on previous United Kingdom commitments".
Downing Street proposals for a review mechanism are understood to be created to allay Conservative concerns over the Prime Minister's plan for the whole of the United Kingdom to remain temporarily in a customs union with the EU after Brexit.
The Sunday Times report said preparations for a final Brexit deal were "far more advanced than previously disclosed" and that May's agreement would satisfy both remain-voting Tories and the hardline Eurosceptics within her party.
Boris Johnson has used an article in The Sun to warn his former cabinet colleagues to "read the small print because we are about to be trapped".
United Kingdom to Slap New Tax on Technology Giants
But these increases will now come into effect 12 months ahead of schedule at the start of the next tax year on April 6, 2019. The tax would raise £ 400m per year by 2022-23.
A spokesperson said: 'The prime minister has been clear that we are making good progress on the future relationship and 95 percent of the withdrawal agreement is now settled and negotiations are ongoing'.
The move could win over some opposition Labour lawmakers and increase the chances of getting a Brexit deal through Parliament, the Times said.
Justice Minister Charlie Flanagan said he wouldn't add to what he described as "speculation".
The UK is looking for an agreement based on an improved version of the EU's "equivalence" system of financial market access.
"I think it is possible to get a deal in November", he said. "We hope a deal can be done but we're not there yet".
Mr Coveney's spokesperson said the European Union had been united through the Brexit process and the UK had given written commitments that the Withdrawal Agreement would give a legal guarantee of no return to a hard Border in Ireland in any circumstance.
The EU deems a backstop necessary to ensure there is no return to a hard border between Ireland and Northern Ireland, if the United Kingdom and the EU are unable to secure a long-term free trade deal after the end of the Brexit transition period in 2020.
"He recalled the prior commitments made that the backstop must apply "unless and until" alternative arrangements are agreed".