Walesa's comments come as a series of opinion polls show a growing lead for the campaign rallying British voters to leave the 28-nation EU in a landmark referendum on June 23rd.
“Germany in particular must calculate what would be better for development (of the EU): do we create a completely new organisation… or do we fix the old EU?” Walesa told AFP during an interview in Gdansk, the cradle of Poland's 1980s anti-communist Solidarity movement.
“It's up to the Germans to decide because they are the leaders and they must also decide with whom they want to build” the new EU, he added.
The Nobel Peace Prize winner – renowned for negotiating a bloodless end to communism in Poland in 1989 – also insisted that Germany, along with EU partners France and Italy, “should have a contingency scenario prepared to put in place 15 minutes after the EU falls apart.”
“After the current European Union falls apart, a new union must be created, but it must be thought out much better in order to avoid the kind of problems we have now.
“Whoever wants to join it, can join, while those who don't, can just say 'no thanks',” Walesa said.
The 72-year-old veteran Polish statesman believes the crisis gripping the 28-member European Union is rooted in its lack of shared values.
“Europe, this European construction has no foundation.
“We rejected Christianity, we rejected ideologies like communism and now, there's nothing left. What can we expect from societies when each of them has different foundations?”
An ardent globalist, Walesa also believes it is high time for a more federal Europe based on greater political and economic integration.
“Changing mindsets is the most difficult thing. Our mindsets are still strongly anchored in the old divisions between states.
“But the notion of the state as the most important, is something from the past: Germany, Poland, no, that's finished. Europe is the overarching value.”
The former shipyard electrician, who as the Solidarity union leader was central to changes that saw Poland shed communism in favour of capitalism in 1989, believes that repairing the EU is preferable to rebuilding it from scratch.
“I'm rather more in favour of repairing what we already have. What's the use of starting all over again?
“But we need to do it (repair the EU) in a more efficient and transparent way. We have to explain things better to people; they need to understand what we're doing and why it (the EU) exists.
“What we've got now is mistrust, suspicions, bureaucracy, dissatisfaction and trickery, because we don't have any solid foundations!”
Poland and other eastern EU members are particularly keen to see Britain to stay.
Some 800,000 Poles and hundreds of thousands of Czechs, Slovaks and Hungarians have migrated there seeking jobs and a better life since the EU's eastward expansion in 2004.
In the event of a Brexit, Walesa believes his own country should continue to be firmly anchored in European structures.
“Regarding Poland, either we get involved in this Union straight away, or we'll be sidelined and after 50 years we'll join it anyway.”