Michel Barnier warns Theresa May EU will not extend Article 50 without new Brexit plan
Theresa May has been warned by Michel Barnier that the UK must come up with a clear "plan" if it wants to delay Brexit.
The EU's chief negotiator spoke out as the Prime Minister prepares to send a letter to Brussels formally requesting an extension to the Article 50 process.
Mr Barnier suggested that a second referendum or a general election could be two reasons to authorise a delay.
He also ruled out the possibility of Mrs May asking for a short extension while seeking a longer one as a backup.
Speaking at a press conference, the top EU official said any extension must be "linked to something new, a new political event, a new political process".
He added: "If not, what would the purpose and outcome be for an extension. And how can we ensure at the end of a possible extension we are not back in same situation?"
"In any case the European Council will need to assess what is in best interests of the EU, extending uncertainty without a clear plan would add to economic cost for our businesses but also incur a political cost for the EU.
"If we have a long extension we are concerned about the major challenges Europe has to face. I can't jump the gun on what [EU leaders] answer to Mrs May will be. But they will ask Mrs May why she wants an extension and for how long."
Asked how the EU might respond if Mrs May requested a short and long extension, Mr Barnier said: "Both short and long? It is either one or the other, isn’t it?"
Meanwhile, John Bercow - who yesterday sparked fury by blocking a third vote on Mrs May's deal unless "substantial" changes to it are made - confirmed MPs will get the final say on any attempt to extend Brexit beyond 29 March.
He told MPs: "A successful application would not only require the agreement of the Union but in the first instance… it would require the agreement of the House and we will have to see whether in due course that will be sought.
"But certainly the agreement of the House is a prerequisite. I am pretty sure about that and the agreement of the Union would also be required."
Downing Street admitted for the first time on Tuesday that it is now impossible for the UK to leave the EU with a deal on 29 March.
A spokesman for the Prime Minister said: "She is absolutely determined to find a way to deliver on the verdict of the British people as quickly as possible. She wanted to leave on March 29. That has not proved possible."