Verhofstadt, an influential MEP who was Prime Minister of Belgium from 1999 to 2008, said on Twitter today that Brexit should be delivered by 2019, when EU politics enters into a "new cycle" and the European Parliament starts its new mandate.
He also stated that if the UK wants to retain access to the Single Market, it "must also accept the free movement of citizens".
If UK wants access to #SingleMarket, it must also accept the free movement of citizens. Our four freedoms are inseparable.— Guy Verhofstadt (@guyverhofstadt) September 13, 2016
His comments came ahead of tomorrow's State of the European Union address, to be delivered by Jean-Claude Juncker.
Verhofstadt was named the European Parliament's Brexit point man last week - an appointment that ruffled some feathers.
London MEP Syed Kamall described the move as a "backroom stitch-up" and said the decision should have been voted on.
"It is not right that the President and a couple of men sitting in a back room can decide everything and foist it on the democratically elected representatives," Kamall added.
Meanwhile, ex-Ukip leader Nigel Farage has (correctly, it seems) predicted that Verhofstadt's appointment would mean a speedy exit from the EU.
"Guy Verhofstadt hates everything we stand for which should mean a much shorter renegotiation," he commented.