SALZBURG, Austria (Reuters) - European Union leaders will push for a Brexit deal next month but warned Prime Minister Theresa May on Thursday that if she will not give ground on trade and the Irish border by November they are ready to cope with Britain crashing out.

“Don’t worry, be happy,” joked EU chief executive Jean-Claude Juncker after telling reporters after a summit in Austria that the Europeans had full plans in place in the event there was no deal before Britain leaves next March.

May promised new proposals to reassure Dublin that it would not get a “hard border” with the British province of Northern Ireland but warned she too could live with a no-deal outcome -- though many round the summit table in picturesque Salzburg see that as more of a negotiating tactic than a credible threat.

She said her “Chequers” proposals for trade with the EU, intended also to resolve arguments over the borders of Northern Ireland, were the only way forward. EU leaders repeated their view the plans would undermine their cherished single market.

But leaders also tried to put a positive spin on their 24 hours of talks. Summit chair Donald Tusk said he was more optimistic about getting agreements both to ease Britain out gently and to sketch out a future free trade pact.

Tusk said a Brussels summit on Oct. 18 would be a “moment of truth” to overcome remaining big problems and leaders pencilled in the weekend of Nov. 17-18 to formalise a final agreement.

But May and German Chancellor Angela Merkel were among those who stressed there was still “a lot of work” to do.

May faces a fight with angry Conservatives at her party’s conference in 10 days. They deride her willingness to bind Britain into much EU regulation in return for free trade; some would prefer a no-deal “hard Brexit” in March, despite warnings that would ravage the British economy.

EU leaders understand that she can give little away before the conference ends on Oct. 3. But they hope their negotiator, Michel Barnier, can secure her agreement next month to what will be new EU proposals. These will be fundamentally unchanged but may be politically more palatable, notably on Northern Ireland.

“Ritual dance is always a part of such negotiations,” a senior adviser to one of May’s summit peers told Reuters.

“It may be that they will just accept what we have proposed after the Tory conference.”

MERKEL, MACRON SCEPTICAL

Whether it can be done by mid-November, many doubt. Brussels is familiar with the theatre of diplomacy, where being seen to hold out to the bitter end can help sell the unpopular back home and some diplomats believe a deal could take until Christmas.

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Any later, and there would be a risk of failing to get it ratified by both parliaments before Brexit Day on March 29.

“It was clear today that we need substantial progress by October and that we then aim to finalise everything in November,” Merkel said. “But there is still a lot of work to do on the question of how future trade relations will look.”

“You can’t belong to the single market if you are not part of the single market, but you can develop a lot of creativity to find practical, good, close solutions.”

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French President Emmanuel Macron rammed home the message: “It was a good and brave step by the prime minister,” he said of her trade plan. “But we all agreed on this today, the proposals in their current state are not acceptable.

“The Chequers plan cannot be ‘take it or leave it’.”

The EU also insists on a “backstop” clause in any withdrawal treaty. This would keep Northern Ireland under EU economic oversight if London and Brussels cannot agree a trade pact to keep UK-EU borders open after a transition period ends in 2020 -- an idea that May and a small party in the province that props up her minority government oppose.

“We need to ensure that nothing is done which effectively carves Northern Ireland away from the rest of the United Kingdom,” May told reporters after Tusk had briefed her on the discussions the other 27 had on Brexit over lunch.

Irish Prime Minister Leo Varadkar said there was no chance the EU would compromise on its demands and rejected speculation the other countries would be tempted to fudge the Irish issue until later. But he also said he thought there would be a deal.