EU-UK ties won't be "frictionless," but there's no need for a wall between neighbors, EU Council President Tusk has said. Still, guidelines he presented pour cold water on British calls for a post-Brexit free trade deal.

Britain's departure from the EU according to its own red lines would damage UK-EU trade and "limit the depth" of any future economic partnership, the EU warned on Wednesday, DW reported.

The warning comes days after May called for the "broadest and deepest possible agreement" to protect existing trade relations after Brexit occurs in March 2019.

In a document presented by Tusk, the EU said a post-Brexit trade deal would not make up for the British decision to leave the EU customs union and single market: "Being outside the customs union and the single market will inevitably lead to frictions [in trade]." This, it added, "will have negative economic consequences."

Britain cannot "cherry-pick" getting free access to certain EU benefits without having to pay the costs of being a fully fledged member of the bloc. Some British politicians have called for the UK to have unfettered access to parts of the EU internal market after the country's departure.

Any deal on financial services trade needs to reflect that Britain and the EU "will no longer share a common regulatory, supervisory, enforcement and judiciary framework."

Britain would also have to agree to safeguards in a deal to ensure London cannot undercut EU regulations after Brexit. May had promised in a speech on Friday that Britain would maintain high standards in line with those of the EU.