The Labour leader, 68, has ruled out the prospect of his party supporting a second referendum on European Union membership.
And he said he intended to be ready to fight an election at any time and was pursuing a healthy lifestyle, including porridge for breakfast, to keep himself in good shape.
Mr Corbyn claimed Theresa May’s position was so “unstable” that she could be forced to call an election within 12 months, but said he was ready for the long haul if the minority Tory government remained in office until mid-2022.
The Labour leader said he and the party were determined to build on its advances since the June general election when it defied predictions to make steady gains.
Asked whether he could sustain that momentum for another four years, Mr Corbyn replied: “We’ve got lots of energy. I’ve got loads of energy, I’m fine. I eat porridge every morning – porridge and energy bars – and I keep off alcohol and meat.”
Mr Corbyn stood by an earlier forecast that he could become Prime Minister during 2018, saying: “The scenarios are that the Conservatives implode to some degree or their position becomes untenable and they decide to call another election, and we’ll take the battle out there.” Mr Corbyn’s immediate challenge is to translate Labour’s healthy opinion poll ratings into gains in May when local elections are held in London, Birmingham, Manchester, Leeds, Newcastle and other major cities.
He said the party would campaign on the impact of austerity on council services, adding: “I am hoping we do very, very well, but I’m not putting a figure on it.”
Reflecting on Labour’s extraordinary turnaround this year, Mr Corbyn said: “The key factors were the registration of a lot of new voters, the production of our manifesto, which was transformational, and an exciting campaign that was a combination of the very old-fashioned (with) public rallies on the streets and parks and so on around the country.”
He added: “I did 100 events myself during the general election campaign and travelled the length and breadth of the land on it. We didn’t quite win – that’s my great regret.”
Some of Mr Corbyn’s MPs have backed holding a vote on the eventual Brexit deal and his deputy, Tom Watson, has said nothing should be ruled out.
However, Mr Corbyn categorically dismissed support for a second Brexit vote. “He (my deputy) did say that, but our position is that we are not advocating a second referendum,” he said.