The world’s most powerful banker has attacked socialism, saying it produces “stagnation, corruption and often worse”.

JP Morgan’s chief executive, Jamie Dimon, took aim at socialism in his annual letter to shareholders, and warned it would be “a disaster for our country”.

Dimon, who was paid $31m last year as the head of America’s largest bank and who is estimated by Forbes to be worth $1.3bn, took his swipe as a new wave of left politics has emerged in the US.

Democratic socialism has been embraced by a new generation of politicians, including New York congresswoman Alexandria Ocasio-Cortez, and supporters of Bernie Sanders, a longtime socialist now making a second bid for the presidency.

Dimon’s attack also comes as many leftwing Democrats, including Sanders and Senator Elizabeth Warren, have called for the breakup of big businesses and greater regulation of banking in particular.

In his letter, Dimon wrote: “When governments control companies, economic assets (companies, lenders and so on) over time are used to further political interests – leading to inefficient companies and markets, enormous favoritism and corruption.”

He went on: “Socialism inevitably produces stagnation, corruption and often worse – such as authoritarian government officials who often have an increasing ability to interfere with both the economy and individual lives – which they frequently do to maintain power. This would be as much a disaster for our country as it has been in the other places it’s been tried.”

Socialism is set to be one of the key issues of the 2020 election cycle. Donald Trump has already begun campaigning against socialism and used his State of the Union address to declare that “America will never be a socialist country.”

Dimon has previously warned income inequality is dividing America.

“It is absolutely obvious that a big chunk of [people] have been left behind,” Dimon said last month. “Forty percent of Americans make less than $15 an hour. Forty percent of Americans can’t afford a $400 bill, whether it’s medical or fixing their car. Fifteen percent of Americans make minimum wages, 70,000 die from opioids [annually].”

In his letter, Dimon acknowledged capitalism’s “flaws” but praised it as “the most successful economic system the world has ever seen”.

He wrote: “This is not to say that capitalism does not have flaws, that it isn’t leaving people behind and that it shouldn’t be improved. It’s essential to have a strong social safety net – and all countries should be striving for continuous improvement in regulations as well as social and welfare conditions.”