U.K. and European Union officials failed to agree on a start date for Brexit negotiations amid uncertainty in London over Prime Minister Theresa May’s plans for a post-election government. A meeting in Brussels on Monday between EU chief Brexit negotiator Michel Barnier and Oliver Robbins, the head of the U.K.’s Department for Exiting the European Union, broke up without any firm commitment on when to begin the process, according to a person familiar with the talks. EU officials say they are still unclear about what the U.K. wants out of Brexit and are frustrated about delays in getting around the negotiating table. May’s dismal showing in last week’s snap election has thrown EU plans to begin negotiations on June 20 into chaos. Questions about whether the government’s Brexit position may now change, how long May will remain prime minister and even about when Queen Elizabeth II will give her speech to Parliament formally setting out the new government’s program are adding to uncertainty over when the talks can start. Further meetings between EU and U.K. officials over the structure of the negotiations and the start date might take place this week, the person said on condition of anonymity because the talks are private. “With regard to technical talks, we are quite confident that they can start soon, even this week, and our understanding is that there is a shared willingness on the British side to move ahead with these technical talks,” European Commission spokesman Alexander Winterstein told reporters in Brussels as the meeting got under way. Winterstein declined to set a precise date for moving from “talks about talks” to substantial negotiations “as this doesn’t depend entirely” on the commission, the EU executive. “We are fully ready; we are fully prepared,” he said. Future Relationship Barnier wants the negotiations to begin with discussions over the terms of Britain’s “divorce” from the bloc, before moving onto looking at the two sides’ future relationship. The U.K. wants those two aspects to be discussed together. The EU has been forced into a holding pattern ever since British voters opted to leave the 28-nation bloc in a referendum last June. The government waited nine months after that before officially activating the two-year withdrawal process and May’s surprise call for snap elections delayed the start of talks by around another four weeks. Uncertainty over the weakened government’s Brexit plans now looks set to slow the talks further. While waiting for the U.K., the EU has drawn up detailed position papers on its negotiating position in areas including the safeguarding of citizens’ rights and the bill it wants Britain to stump up based on previous financial commitments. As well as the exact start date, the two sides have to agree on the format of talks. The EU favors holding negotiations in four-week cycles, with one week in each round devoted to discussions between the two sides in a European Commission building in Brussels.