The consequences of a British vote to leave the European Union (EU) would parallel the collapse of U.S. investment bank Lehman Brothers, an event that triggered the global financial crisis, warned Alexander Stubb, Finland's former Prime Minister.
"There's not one economist in the world who would see a Brexit as a good thing to either the United Kingdom (U.K.), EU or global economy....I would say if Britain were to vote out, we would see far-reaching market turbulence," he told CNBC's Capital Connection on Thursday.
Stubb, also Finland's outgoing finance minister, believed the U.K. was an instrumental part of the EU despite its reputation as a "a reluctant bride" ever since it joined the European Economic Community in 1973, referring to the U.K.'s long history of separatist tendencies.
A remain vote would not only strengthen the marriage, the U.K.'s status as a former great empire can help bring more clout to a recovering Europe, he added.
"If the U.K. decides to stay, that will also give a much stronger agenda for economic reform [in Europe]. If we cut red tape and liberalize the internal market for services, goods, capital and people, then all of Europe will be better off."