Germany and France have privately warned the European Union to do more to prevent the U.K. from being able to claim victory in Brexit talks, according to EU diplomats.

In meetings over recent days, the EU’s most powerful governments expressed fears the bloc is giving too much away in the charge to get a deal. Confronting populist anti-EU forces across Europe, leaders want one last opportunity to show that leaving the bloc can’t be as advantageous as staying in, and some have called for stringent conditions to restrict the British economy, according to diplomats present in the talks.

As U.K. Prime Minister Theresa May prepares a flying visit to Brussels to meet EU chiefs this week, negotiators are finalizing a document that will form the basis of the two sides’ future relationship. The text, which falls a long way short of a full trade deal that some pro-Brexit ministers in the government once promised would be ready by now, is due to approved at a summit on Sunday.

EU officials said they are braced for a week of intense diplomacy between London, Brussels, Paris and Berlin. One of the concerns raised by diplomats from Germany was that May shouldn’t be able to get her so-called Chequers plan accepted “through the backdoor.” Earlier this year, the EU rejected the economic proposals of the plan because they didn’t do enough to stop the U.K. having a competitive advantage.

Brexit Consequences

France is leading a group of countries pushing the EU to include a string of conditions as part of agreements on future ties. France’s ambassador told the European Commission in a meeting on Sunday that the EU needs to reiterate that “Brexit should have consequences.”

“We do not want to reopen the agreement but we will be very vigilant about its implementation,” French European Affairs Minister Nathalie Loiseau told reporters in Brussels. “We will be very attentive to the political declaration on the future relationship, on the issues of fair competition.”

One of France’s key demands is that the U.K. commit itself to sticking to the EU’s tough environment standards, even if the EU makes them stricter after Brexit. It also wants Britain to sign up to so-called level playing field restrictions in areas of labor law, state aid and taxation as well as a pledge to allow European fishing vessels access to British waters.

Conditions Attached

Other countries, including the Netherlands, Belgium and Denmark, are making their own demands. While they’ll back plans to offer the U.K. an “ambitious” free-trade deal, they’ve warned that the deeper it is, the more conditions could be attached. They’ve suggested that conditions to ensure that Britain can’t undercut the European economy could also cover services, according to one diplomat.

In the meetings with governments, Michel Barnier, the EU’s chief Brexit negotiator, cautioned against piling more conditions onto the U.K. for fear that it would open the way for Britain to push to reopen the divorce treaty that both sides declared done last week, according to the diplomats.