In a fiery interview, MEP Elmar Brok also hit out at Theresa May and demanded more “clarity” from her and her negotiating team.
And the CDU politician warned “Britain can not cherry pick” the terms of their future relationship with the EU – the bloc’s most popular go-to Brexit threat.
The combative MEP let fire in a question-and-answer session for German newspaper Passauer Neue Presse today.
When asked what he thought of the UK’s negotiating tactics, he warned Britain faced a “very hard” Brexit unless they played by the rules.
He said: “The British must follow the terms of the transitional arrangements so that we have time to negotiate a trade agreement by 2021.
“If they do not agree to these rules, we will have a very hard Brexit at the end of March 2019.
“Then March 29, 2019, exactly two years after the submission of the exit request, will mark the end.
“The British were the ones who wanted Brexit. Therefore they have to accept the conditions now. We expect clarity from Mrs May.”
But he said the opportunity remained for Britain to remain in the union – even if such a scenario was not likely.
Mr Brok said: “That would be desirable. But the time window is so small that it seems unrealistic. There is only one year left.
“There are currently no political forces in London who really want it.
“The door is open, but I do not see enough movement to take that step. The catastrophic consequences of Brexit for the economy and the job market will only be felt in two years in Great Britain.
“If it comes to a Brexit, this should be clearly regulated. At least there should be a far-reaching trade agreement. One thing must be clear: Britain can not cherry pick.”