The two-year negotiation process between EU Brexit chief Michel Barnier and Britain's Brexit minister David Davis had been due to formally start on June 19.
But that looks increasingly unlikely as Conservative British Prime Minister Theresa May fights for her political life after unexpectedly losing her majority in parliament.
In Brussels on Wednesday Barnier instead met Olly Robbins, a senior official in Davis's ministry, and Britain's ambassador to the EU Tim Barrow to discuss arrangements for the talks following the election shock.
"The EU stands ready to begin negotiations."
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The arrangements under discussion include dates and the sequencing of talks -- the EU wants four-week cycles of negotiations, each covering one topic -- once they do actually get started.
European Commission spokesman Alexander Winterstein earlier declined to provide a likely start date.
"When will be the point from moving to talking about talks, to more detailed talks, I cannot say. This doesn't depend entirely on us," Winterstein told a daily briefing.
European Commission chief Jean-Claude Juncker said last Friday that Brussels would be ready "at half past nine" the next morning if Britain was ready.
London has said it wants the Barnier-Davis talks to start as scheduled next Monday, but since Thursday's election it has not formally committed to the date.
Davis told BBC radio today that the government stood by its threat to "walk away" with no deal if talks -- when they do eventually start -- break down.
"Obviously it's not great that things are being delayed," an EU source said on condition of anonymity, adding that Brussels officials had been "glued to their TV screens and Twitter" for the British election results.