warsaw poland want euro zone become strong make decision whether join single currency finance minister mateusz morawiecki say hold finger cross euro zone survive overcome imminent problems ... surely convergence happen author wish morawiecki also deputy prime minister tell journalists would like euro area strong years see cop everything statement suggest soften towards euro zone membership eurosceptic law justice pis party come power two years ago although decline say poland could start think membership friday tell economic forum opponent introduce euro currency poland time right yet let wait five 10 years say pis government say previously flexibility national exchange rate help country difficult time early year morawiecki say economic forum remain see euro zone go part problem part solution eu accord various poll two thirds pole oppose join euro area poland want strong euro zone mull membership finance minister