Downing Street has been forced to deny Boris Johnson has lost control of the Brexit negotiations as French ministers warn of weeks more talks amid “upheaval” in London, and senior Brussels figures claim the chaos had led to a standstill. France’s minister for EU affairs, Clément Beaune, appeared downbeat on Friday about the chances of an imminent breakthrough on a UK-EU deal. There has been scant progress in the last week of the trade and security talks, while No 10 has been shaken by infighting that led to the news that Dominic Cummings would quit as the prime minister’s chief adviser. Beaune said: “We have never set a fixed, scientific deadline for an agreement to be reached, but objectively, rationally, if it happens after the end of November we will be in trouble. “I think a deal is possible; both parties want one. It will require several days, possibly two to three more weeks, of negotiation.” He said of the Downing Street fallout: “This is not the first such development. We have watched all such upheavals over the past four years with interest, but for us a Brexit deal can never be allowed to depend on the vicissitudes of what’s going on in London. “We have to remain calm, courteous but also determined – so we watch, with interest of course, but as people and as politicians, not as negotiators.” Manfred Weber, the leader of the largest party in the European parliament and a political ally of the German chancellor, Angela Merkel, also lamented the “chaotic situation” in No 10. He said: “We can see this as a quite chaotic situation where we don’t have an idea what is really the line in Great Britain. So don’t tell us we should be ready for compromise. “We need a clear idea from Boris Johnson now and I think it’s now time for leadership – having all the developments in America in mind, where London understood it will be not so easy with Joe Biden [as US president-elect] to achieve an easy trade deal now. “It’s time to take over responsibility and come to a common understanding. Britain has red lines, we have red lines, let’s now come to a compromise.” Downing Street responded by insisting that the British negotiating team, led by David Frost, had been unaffected by the recent developments. A UK official said: “David and the team are completely focused on the negotiations. The prime minister has been clear that he wants a deal if there is a deal to be done. We’ve been negotiating constructively and with creativity. “I guess the reason the EU feel the need to say these sorts of things is that they are starting to realise that we meant it when we said there were fundamental principles from which we couldn’t move. We need to see some realism and creativity from their side if we are to bridge the significant gaps that remain.” Brussels had hoped the outlines of a deal could be put before EU leaders at a summit on Thursday but the stasis on the most contentious issues, and the apparent chaos in Downing Street, has prompted anxiety. Sources have warned of a lack of engagement for days from No 10 on the EU’s demands for “level playing field” provisions that will ensure neither side can achieve a competitive advantage through lowering regulatory standards over time or subsidising failing businesses. Cummings, the former campaign director for Vote Leave, confirmed on Thursday evening that he would leave Downing Street by Christmas. However, on Friday night he left with immediate effect. It followed the resignation of Lee Cain, Johnson’s director of communications, who quit after being offered the job of chief of staff by the prime minister before having it rescinded following pressure from people including Johnson’s partner, Carrie Symonds. Cummings has dismissed as “comical” claims that a dispute over how to manage the final phase of the Brexit negotiations was to blame for the crisis in Downing Street. There have, however, been concerns raised in the past by EU officials and diplomats that the prime minister was being “held captive” by former Vote Leave members. One senior EU diplomat said Cummings’ departure offered hope that the UK government’s resistance to agreement with the EU on a future domestic subsidy regime might slacken. “His flawed concept of state aid has held the negotiation hostage,” the diplomat said. Cummings has championed the UK’s future ability to subsidise the tech industry as a major Brexit dividend. Philippe Lamberts, the leader of the Greens in the European parliament, said he believed Cummings’ departure was “probably the sign that Johnson has begun his U-turn and will, in the end, accept EU conditions”. A Downing Street spokesman denied the claim. “Absolutely not – simply false,” the spokesperson said. “The government’s position in relation to the future trade agreement negotiations hasn’t changed.” The EU negotiating team will leave London on Friday and re-engage with their UK counterparts in Brussels on Monday.