We have the Brexit negotiation, we have this ring of autocrats around the EU instead of the ring of friends.
"It seems to me more and more we are surrounded by autocrats. Putin, Erdogan and then, the first appointments of Mr Trump, worries me also a lot," said Guy Verhofstadt, who is the European Parliament's chief Brexit negotiator.
The former Belgian premier added: "What I see today is now Russians and Americans and Turks... working together more and less on European soil to destroy the European model."
Verhofstadt accused Russian President Vladimir Putin of "openly financing" populist and eurosceptic parties and Turkish President Recep Tayyip Erdogan of targeting Turkish opposition members in Europe.
He went on to compare them to the US president-elect, singling out plans by Trump's chief strategist Steve Bannon to open new bureaus of his rightwing Breitbart News website in France and Germany "to influence elections".
Verhofstadt, who leads the Liberal group in the European Parliament, said the three leaders had a "common point of view that they want to bash and ... even destroy our way of thinking, our values."
"We have to fight back, this is a crucial moment in the history of the EU," said Verhofstadt.
"We have the Brexit negotiation, we have this ring of autocrats around the EU instead of the ring of friends. It is the moment to build a real political Union, a strong one, an effective one."