Prime Minister Theresa May complained Thursday that Britain should not be left out of EU discussions, despite the country's decision in a June 23 referendum to leave the bloc. May's 27 European Union counterparts met without her on September 16 in Bratislava to discuss the bloc's future, and they are due to hold another get-together on February 3 in Valletta, Malta. May raised concerns about the Bratislava format during her first appearance at an EU summit in Brussels, several EU diplomats told dpa. "She said Britain does not want to rubber-stamp decisions taken by the 27," one source who was briefed on the meeting said on condition of anonymity. European Council President Donald Tusk replied that it was Britain's own decision to leave the club and that "the 27 will keep on having meetings in the EU 27 format," the source added. Another source told dpa the British leader did not question the need for "EU 27" meetings, but insisted that Britain should be involved whenever EU matters that still affect her country are on the agenda. Proceedings on Britain's exit from the EU, or Brexit, are likely to be acrimonious, and May has signaled that she will not start them before the first quarter of next year.