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On the issue of delaying Brexit by extending Article 50, the BBC's Europe editor Katya Adler says "it is European leaders who will have the final say."

"There is not the appetite to have a long extension which could overshadow not only European elections in May, but also other EU business," she says.

The "nightmare scenario" for EU leaders is a long extension to allow for a general election which could prove "inconclusive".

However she adds that "EU leaders don't want a no-deal Brexit" so may back a long extension if necessary.

"They may say yes through very gritted teeth."