Radek Sikorski warned the Law and Justice Party and Government in Poland, chaired by Jarosław Kaczyński, may eventually lead the country out of the European Union.
Speaking in front of students at Greenwich University, Mr Sikorski said the eurosceptic political movement may spiral out of control, as Mr Kaczyński’s Party try to demand concessions from Brussels.
Mr Sikorski was asked by an audience member: “Do you think the Government of Jarosław Kaczyński now is like another Brexit?”
The former Polish minister replied: “I fear that he may make the same mistake as fellow Europhobes in Britain.
He thinks that he is just trying to get a better deal out of Brussels. Which is what the British Tories tried to do.
“But he has started a rhetoric and a political movement that he may find that in the end, he cannot control.
“He may engineer Polexit without meaning too.”
Former Prime Minister Mr Kaczyński, who is the chairman of the Law and Justice Government in Poland, has played a leading role in the growing eurosceptic movement in Poland.
Former minister Mr Sikorski, who served in Donald Tusk’s cabinet, was also asked whether other EU countries would follow the UK out of the bloc.
He said: “Sure. I mean, we’ve just got a result in Italy where right-wing anti-EU parties have the majority of the vote.
“In Germany, an anti-EU party is gaining ground. You know, we assume that the centre will hold in Germany.”
Mr Sikorski warned that a German EU exit would result in Britain and Poland alike wanting Germany to be back in the bloc – where its global influence would be restricted.
He said: “What if Germany turns against the euro and against the European Union. Then I think all of us, and particularly in Poland and Britain, we will be thinking back to those happy days when the Germans were being European and were willing to circumscribe their power.”