12:03

Theresa May was not invited to a European Union summit in Bratislava soon after she became prime minister. She will have to get used to it.

EU leaders are planning a meeting in December to discuss Brexit without the British prime minister, the Guardian has learnt.

Donald Tusk, the president of the European council, wants the EU’s 27 remaining member states to discuss Brexit around the time of an EU summit scheduled for 15-16 December, according to two Brussels sources.

The British prime minister would attend the EU summit, but would not be invited to separate Brexit talks, the third time the UK has been excluded from leaders’ talks since it joined the bloc in 1973. EU leaders met without David Cameron soon after the Brexit vote and held the summit in Slovakia without Theresa May in September.

The meeting is a sign the EU27 are intensifying preparations on Britain’s EU exit ahead of article 50, which May has promised to trigger by the end of March.

Once the UK fires the starting gun on talks, the EU will spend four to eight weeks drawing up detailed guidelines for negotiations, a list of red lines that could cover everything from the single market to the status of Gibraltar.

That work hasn’t started yet, but Tusk wants to start preparing the ground. One senior EU diplomat told the Guardian the guidelines would be a trade off between speed and precision: “if the guidelines remain flexible they are easier to adopt, if they are very detailed, they are likely to take more time.”

Brussels diplomats are keenly following Brexit fallout in the UK. Some say they have been shocked by the UK media response to the high court decision on parliament’s role and the government’s limited defence of British judges.