Britain needs to face hard choices of Brexit, says Barnier

British politicians need to give up the notion that they can avoid the tough choices resulting from Brexit in order to be able to strike a trade deal "based on the foundation of realism", the EU's chief negotiator has said.

Speaking on the eve of Theresa May's keenly-awaited speech setting out her vision of the post-Brexit relationship between the UK and EU, Michel Barnier said that Brussels was waiting to hear what Britain wanted on issues ranging from trade to security and aviation.

And he made clear that the UK has still not put forward proposals for keeping the Irish border open which might avoid the need for the European Commission "backstop option" - rejected out of hand by Mrs May on Wednesday - of effectively keeping Northern Ireland in the customs union.

"If the UK has better ideas on how to avoid a hard border while preserving the integrity of the single market, we are ready to look at them in a very constructive way," he said.

Speaking to a business conference in Brussels said he hoped Mrs May's address would "help us move the negotiation forward by setting out her vision of the future relationship".

But he warned: "Any vision of the future must take into account the fact that the EU cannot and will not compromise on its founding principles."

Britain faced a choice over whether the freedom to make its own decisions on issues like free movement and strike trade deals with outside states was worth the "consequences" of losing the advantages of the single market and customs union, said Mr Barnier.

"I recognise the political temptation to avoid making a choice or to downplay the cost of Brexit, or indeed to pretend that the UK could obtain a free trade deal with the EU with all the benefits of the single market without the obligations," he said.

"Abandoning such ideas will enable us to begin building an ambitious future partnership based on the foundation of realism and in the interests of our citizens and our businesses, and this is my objective."

Mr Barnier warned that business may have to wait longer than expected for the "certainty" offered by the transition period being sought by Mrs May, which would see the UK observe single market rules for around two years after Brexit to give companies time to adapt.

Although the Prime Minister hopes to get political agreement at this month's European Council summit, the final deal may not be nailed down until early 2019 - just weeks before the official date of Brexit on March 29, he said.

"Of course the transition period currently under negotiation would give you more time to adapt," Mr Barnier told his business audience.

"However, that certainty about a transition will only come after the end of the process with the ratification of the withdrawal agreement by both sides, probably early next year."