Several European Union member states are weighing up what pre-conditions they could demand in exchange for any request from the UK to postpone Brexit, people familiar with the matter said.While the UK is due to leave on March 29, Theresa May has stopped short of ruling out an extension to the withdrawal deadline, and countries including France and Germany have indicated they might support an extension to help avoid the UK crashing out without a deal.Among the conditions being considered is that any talks after the extension shouldn’t involve reopening the withdrawal agreement or the controversial backstop to avoid a border returning in Ireland, one of the EU officials said. Another country wants the UK to set down in writing what it wants from any new talks, a second official said. Both asked not to be named, as deliberations are ongoing.There’s been no collective, detailed discussions on pre-conditions, one of the people said. But there’s a wariness of entering an extension just to allow May to continue to try to forge a consensus on the way forward in London.Sabine Weyand, the EU’s deputy chief Brexit negotiator, said on Monday the EU would demand there should be clarity by the end of the extension period. She also said there shouldn’t be ‘serial extensions,’ as Brexit is already ‘eating up political energy’ in the bloc.Nonetheless, there’s an expectation that the UK would be granted an extension if requested as both sides remain anxious to avoid a no-deal scenario. Lithuanian president Dalia Grybauskaite, one of the European Union’s most outspoken figures, said last week the EU will probably be “helpful” to the UK if it asks to postpone. But ‘the longer we will drag both sides in the process the more damage we will make,” she said.