The EU set a deadline of October - when leaders are scheduled to meet in Brussels - to decide if "sufficient progress" has been made on the exit bill, citizens' rights and the Northern Ireland border issue.
"I would like to be clear that I did read with the requisite attention all the papers produced by Her Majesty's government; I find none of them truly satisfactory".
It was hoping the papers would persuade the European Union that talks about the future relationship should be brought forward, arguing that divorce issues such as the Irish border will be easier to settle once the terms of a trade deal are clear.
"We can not mix these issues up", he continued.
The talks take place amid continued turmoil in Britain, with the Opposition Labour Party over the weekend backing a "soft" Brexit whereby the country remains in the EU's customs union and single market for a transition period.
"There are an enormous amount of issues which remain to be settled".
Hours after his chief negotiator Michel Barnier urged his British counterpart to "start negotiating seriously" when they met in Brussels on Monday, European Commission President Juncker echoed the bloc's refusal to discuss the future free trade deal London wants before pencilling in terms for leaving the EU. He added, "they have made it quite clear that we can not honor the decision of the referendum if we remain in the customs union and the single market".
She added: "We have just begun the third round today; we felt the first two rounds were positive and constructive, and as you've seen over the summer we've published numerous position papers, as well as future partnership papers".
The negotiations are now stuck, in the British view because of commission inflexibility, and in the commission view, because we haven't set out enough detail on vital preliminary matters, including our financial obligations.
Barnier said United Kingdom to start negotiating "seriously", calling on the British government to set out its position on paying an exit bill before discussing any future post-Brexit relationship. Mr Davis said the papers "should form the basis of what I hope will be a constructive week of talks".