Story highlights Labour's leaked manifesto sets out plans for renationalization and increased public spending

Opinion polls suggest many voters do not see Jeremy Corbyn as Prime Minister

London (CNN) Theresa May's main challenger for prime minister in next month's general election is offering UK voters the most left-wing, big government policy agenda for nearly 40 years.

Under a plan which amounts to a charter for left-wing populism, Labour leader Jeremy Corbyn wants to renationalize large chunks of British industry, the railways and postal service, increase spending on health and schools, put up taxes for business and hike pay for public sector workers.

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The plan was revealed in leaks to the British media on Wednesday evening, and the details were not disputed by party officials during the day. The final version of the plan was agreed on Thursday afternoon, and Corbyn said the policies would prove "very popular" when they are published in the next few days.

There has already been a predictable backlash from Corbyn's critics, including Britain's Daily Mail newspaper, whose front page headline described it as "a manifesto to drag us back to the 1970s" -- a reference to an era of nationalized, unionized industry and high taxes under a Labour government.

But beyond Westminster, the policies -- which Labour says are "for the many, not the few" -- are likley to appeal to voters who are concerned about rising energy bills, overcrowded commuter trains and real-terms cuts to school budgets.

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