Boris Johnson has rejected leaked claims overnight that the government has proposed “customs clearance zones” to tackle the Irish border issue.
Government sources told the BBC it had prepared the legal text of an updated Brexit deal and would be making more plans public in the coming days.
But Mr Johnson told BBC Breakfast he was “not going to be producing now what we are going to be tabling” to the EU.
The leaked proposals were “confused” and “not right”, the PM added.
He said this was the “moment the rubber hits the road” in negotiations and the UK would making “a very good offer” to the EU.
The issue of the Irish border – and how to keep it free from border checks when it becomes the frontier between the UK and the EU – has been a key sticking point in Brexit negotiations.
The current government says the solution reached by the EU and Theresa May, the backstop, is unacceptable and an alternative to it must be found.
The BBC’s Iain Watson said according to leaked proposals, the government accepts there must be customs checks on the island of Ireland, but they would be conducted away from the border.
Customs formalities would be carried out mostly where goods originate or at their final destination.
The Irish broadcaster RTE had reported that a “string of customs posts perhaps five to 10 miles away from the frontier” had been floated by the UK.
But the prime minister insisted “that’s not what we’re proposing at all”.
Mr Johnson was speaking at the start of the third day of the Conservative Party conference in Manchester.
The government has made a raft of policy announcements, including raising the National Living Wage over the next five years and investing into roads and bus networks.
But the plans have been overshadowed by allegations that Mr Johnson squeezed the thigh of a journalist under a table at a lunch in 1999.
Asked about the allegation by Charlotte Edwardes, the PM told Breakfast: “They’re not true. It’s obviously very sad that someone should make such allegations.”