Former British Prime Minister David Cameron has blamed populism for his defeat in the Brexit referendum, and claimed the euro currency may soon collapse in his first major speech since standing down.

Mr Cameron added that although he did not think the European Union (EU) itself would fall apart, the currency was in serious danger, saying he “wondered how long it can last”.

He told students at DePauw University, Indiana: “Some countries have seen decades of lost growth. Those countries have a single currency but they don’t have a single fiscal system, a fiscal tax system. It creates bigger differences.

“You in the United States have ways to make sure that if you have a bad year you pay less in taxes and offset federal programmes. There are no such arrangements in Europe.”

The Mail reports Mr Cameron also told EU leaders to address voters’ concerns as the anti-establishment movement grows across the continent.

“If we don’t address the concerns of those economically left behind, we open up our politics to the parties of the extreme left,” he said.

“And if we don’t address the concerns of those left culturally behind, we open up to the parties of the extreme right.”

In a reference to one of the main policies of U.S. President-Elect Donald Trump, Mr Cameron said Europe did not need border walls to combat mass immigration, despite recent efforts by Hungary and Slovenia.

“We know that immigration has benefited both our countries,’ he said. “But we need a system of control.

“And we may not need a wall, but we do need borders that work and are seen to work. We need that in Europe, just as in the United States.”

The former Prime Minister also acknowledged that he lost his job due to “populism”, but said he remained optimistic that the European establishment can find ways to “combat” the movement.

“I stand here as a great optimist about how we can combat populism. It may seem off that I’m so optimistic, after all, the rise of populism cost me my job ,” he said.

He concluded by praising globalisation, and called on the President-Elect not to “go down the protectionist route”.

“The greatest question is clearly this: does the Brexit vote and the election of your president mean an end to globalisation. I would say very clearly: no.

“It’s not just that the benefits of globalisation are so clear. You have to ask yourself whether it really would be in the interests of the US to go down the protectionist route.

“And the answer is: it is absolutely against your interests. If you start to protect against existing industries, others will undoubtedly start to protect against new ones emerging in the future.”

David Cameron resigned after staking his political future on Britain voting to remain in the European Union. He had campaigned strongly for the Remain side, and the vote for Brexit was seen as a crushing humiliation from which he could not recover.

His successor, Theresa May, has promised to honour the vote to take Britain out of the EU.