European Commission President Jean-Claude Juncker has delivered a fresh rebuke to British Prime Minister Theresa May over her government's handling of the Brexit process.
Juncker said official papers setting out the UK's positions were not satisfactory and it was "crystal clear" that an "enormous amount" of issues needed to be settled before talks on a future trade deal could begin.
Officials from Brussels and the UK were continuing negotiations in the latest round of the withdrawal process, but Juncker's comments are further evidence of the European Union's frustration with the approach being taken by May and Brexit Secretary David Davis.
His comments came after Brussels' chief Brexit negotiator Michel Barnier said he was concerned about the lack of clarity and insisted "we must start negotiating seriously".
Juncker said the UK "hesitates showing all its cards" but added: "I did read, with the requisite attention, all the papers produced by Her Majesty's government and none of those is actually satisfactory.
News that makes sense
Your trusted source for staying up-to-date with the world around you. Get free daily news updates and analysis, straight to your inbox.
"So there is still an enormous amount of issues which remain to be settled.
"Not just on the border problems regarding Ireland and Northern Ireland, which is a very serious problem in respect of which we have had no definitive response, but we also have the status of European citizens living in the UK and UK citizens living on the Continent.
"We need to be crystal clear that we will commence no negotiations on the new relationship - particularly a new economic and trade relationship - between the UK and the EU before all these questions are resolved."
Juncker added: "First of all we settle the past before we look forward to the future."
Davis insisted the UK position papers produced in recent weeks - on issues including Northern Ireland and the continued access of goods to market - were strong in detail.
"They are the products of hard work and detailed thinking that has been going on behind the scenes not just the last few weeks, but for the last 12 months, and should form the basis of what I hope will be a constructive week of talks."
