The EU foreign affairs chief was speaking in Rome, where she was given an award by the Italian Institute for International Political Studies (ISPI).
The Presidential elections in Poland on 24 May were won by eurosceptic Andrzej Duda, a result that has alarmed the government, which faces its own election race later this year.
>> Read: Conservative candidate wins Polish presidential election
Duda, who is currently an MEP, comes from the opposition Law and Justice party of Jarosław Kaczyński, a Eurosceptic force affiliated to the Alliance of European Conservatives and Reformists (ECR). Law and Justice is close to the Catholic church and socially conservative.
With parliamentary elections due in late October, the defeat of outgoing president Bronisław Komorowski, an ally of Prime Minister Ewa Kopacz and a former Civic Platform lawmaker, will weigh on the EPP-affiliated party’s chance of re-election.
The head of Civic Platform’s parliamentary caucus, Rafal Grupinski, said he feared Duda’s win would mean “potential state modernisation moves” would be blocked for the next five years. The change in Poland’s president could eventually lead to a change in Poland’s foreign policy, particularly with regard to the European Union, agencies wrote.
In Spain, the regional and local elections marked the surge of new political forces, the anti-austerity Podemos and market-friendly Ciudadanos, overturning a two-party system that has seen the PP and rival Socialists alternate in power since the end of dictatorship 40 years ago.
>> Read: Local election sends shockwaves to Spanish political establishment
In her speech, Mogherini said that 65 years after the Schuman declaration of 9 May 1950, which proposed to create a new form of organisations of states in Europe, the future of the EU could not be abandoned to the simple confrontation between pro-europeans and eurosceptics.
“The elections’ results in Poland and Spain, albeit very differently, and news from Greece and the UK, tell us that there is a real need of rethinking our being European if we want to save the project of our founding fathers,” Mogherini said.
She argued that it was particularly important to preserve the basic value of diversity in Europe.
“We will remain true to then project of our fathers also if we accept also those who have a father different from ours. It will not be Europe if it gets filled with new ghettos, of new marginals, if we make it live in the fear of the other. Our history, European history has taught us that the other is us,” Mogherini said.