Britain's plan for a temporary customs "backstop" to solve the Irish border issue is "not acceptable" and any fall-back option cannot be time-limited, the European Parliament's chief Brexit co-ordinator has told MPs in the UK.
Guy Verhofstadt said the Government's position that the backstop of continuing UK alignment with the EU customs union would cease by the end of 2021 if no other solution was found left him "puzzled".
Addressing MPs in London today, the former Belgian prime minister said his understanding of a backstop was "a permanent system that is there that you don't use", saying the EU would seek a deal over the key Brexit sticking point.
He told MPs on the Exiting the European Union Committee: "I have never seen a backstop that is used for one year and then it disappears.
"No, a backstop is a fall-back position that you have in your pocket and you hope that you have never to use it. That is a backstop, in my opinion."
"That (the temporary backstop) was not in the proposal of the UK Government. I'm a little bit puzzled by the way the UK Government sees now that problem."
Mr Verhofstadt was speaking at the first of two grillings by MPs in Westminster today.
Yesterday, Brussels warned that serious differences remain over how to deal with the Irish border after Brexit.
Advances have been made in a number of areas, such as customs, VAT and nuclear waste regulation, chief negotiator Michel Barnier said, but "a lot more work" needs to be done to meet the October deadline.
Today marks a step forward in these negotiations - we have agreed a number of separation issues and the #UK has engaged on others. But we are not there yet: serious divergences remain on the backstop for NI/IE. More work clearly needed: https://t.co/w3Vw39w8Nr #Brexit— Michel Barnier (@MichelBarnier) June 19, 2018
Mr Verhofstadt said that ending the backstop in 2021 would mean customs authorities would have to apply three different systems in three years, which was something to "avoid absolutely".
He said he was looking forward to the UK Government's White Paper, due to set out the position on leaving the EU.
He added: "I think that is it still possible to have for October/November an agreement on the political declaration. For that we need to speed up, certainly the negotiations in the coming months."