Jeremy Corbyn has dismissed the “hysteria” and “deliberate misrepresentation” of his campaign’s policies and said that he is committed to ensuring that the Labour party defeat the Tories in 2020 with “people’s politics”.

The leadership candidate has argued that despite attacks directed at his campaigns policies, the message his team are sending out is “resonating”.

In an article in The Times (£), Corbyn has brushed off the idea that his policies are “extreme”, which has been suggested by some Labour politicians including leadership contenders. His opposition to austerity is “mainstream economics”, he says. This comes following a group of economists wrote in defence of his anti-austerity policies over the weekend.

“What is extreme is not the popular proposals we are putting forward but this government’s cynical attempt to pay for a crisis on the backs of the poorest and most vulnerable. This was a crisis brought about by rampant speculation in the City and the deference of successive governments to that corporate lobby,” he writes.

Corbyn said that under his leadership Labour would become “a campaigning force dedicated to defeating the Conservatives’ politics, and then to defeat them electorally in 2020”.

Liz Kendall and Yvette Cooper have in recent weeks argued that a victory for the Islington North MP could result in Labour being relegated to opposition for a decade. It has been said that some of Corbyn’s supporters are resigned to defeat in 2020.

Corbyn also writes that he would “democratise and open up our politics”. In an indirect response to those suggesting the party could potentially split under his leadership, he has said that he will “appoint a shadow cabinet of all talents within the parliamentary Labour party.”

He expanded upon this idea last night at a Guardian hustings, in which argued that policy should be decided by party members. “I don’t think we can go on having policy made by the leader, shadow cabinet, or parliamentary Labour party. It’s got to go much wider. Party members need to be more enfranchised. Whoever is elected will have a mandate from a large membership,” he said.