European Commission President Jean-Claude Juncker joined the European Union’s chief negotiator, Michel Barnier, in lashing out at the U.K. for failing to prepare adequately for Brexit talks. “I’ve read all the position papers produced by Her Majesty’s government and none of them is satisfactory,” Juncker said on Tuesday at a conference in Brussels, as talks between the U.K. and the EU resumed. “There is still an enormous amount of issues that remain to be settled.” The stage had already been set for an intense round of negotiations afterBarnier and Brexit Secretary David Davis met on Monday for the first time since July and candidly aired their frustration at each other’s approaches. Barnier said time was running out, as the U.K. continued in its bid to change the order of topics discussed. The U.K. has published 11 documents outlining its positions in areas that need to be settled as part of its withdrawal from the EU, ranging from data protection to nuclear safety and customs arrangements. While the U.K. hoped the papers would persuade the EU to deal with their future relationship at the same time as the most pressing separation issues, European diplomats criticized the documents for being unrealistic and failing to nail down what the U.K. was asking for. It hasn’t produced a document on the financial settlement—one of the main areas the EU wants to discuss first. Political Push “We must start negotiating seriously,” Barnier told reporters as he stood alongside Davis before their meeting on Monday. “The sooner we remove the ambiguity the sooner we will be able to be in a position to discuss the future relationship and a transitional period.” A plea for flexibility was rejected by Barnier. While the EU is sticking to the plan of negotiating the divorce before moving on to the future relationship if a European summit in October approves it, the U.K. camp says negotiations could progress if Barnier were more flexible. The U.K. is also reluctant to agree to an exit bill without having something to show voters in return. “You can’t resolve these issues technically or legally, it requires a political push and that will have to happen at the October European Council,” Mujtaba Rahman, managing director for Eurasia Group in London, said on Bloomberg TV. “Theresa May can’t write a check for 35 billion pounds, or however much it is going to be, without having something in return—she needs a deal and I think that will have to happen in October, and if not October then December.” The U.K.’s bill remains the biggest stumbling block, and while the U.K. has accepted it will pay something, Davis appears determined not to tell the EU where it accepts it’s on the hook. He told the BBC that this was part of his negotiators’ “constructive ambiguity” approach to try to obtain a better deal. The U.K. also argues that the key issue of the U.K’s future border with the EU, running through the divided island of Ireland, will be easier to sort once the future relationship is clear. Neither side is expecting much of a breakthrough this week even as both British and German business lobbies came together Monday to call for “clarity and certainty.” Davis won’t be present at the talks, leaving his colleagues to figure out how to keep the Irish border open, the status of citizens living in each other’s countries and the infamous bill. Undeterred by Juncker’s comments, the U.K. said Tuesday it will continue to produce position papers in the coming weeks. “We believe we are in a good position and we would like to move on to discuss our future relationship,” May’s spokeswoman Alison Donnelly told reporters in London.