Jeremy Corbyn insisted he was "not going anywhere" as he prepared to mark his first 100 days as Labour leader with a defiant message to hostile MPs.
In an interview with the Sunday Times, he said people should not "obsess" about him but rather put their talents to work for the party.
And he did not rule out a shadow cabinet reshuffle to remove critics.
Asked if he expected to lead the opposition in the 2020 general election campaign, he said: "Absolutely. I'm not going anywhere."
He urged MPs to "recognise" the scale of grassroots support that swept him to a surprise landslide victory in the election contest and denied critics were being targeted by a "mob" of Corbynite backers.
Deputy leader Tom Watson has described the pro-Corbyn Momentum organisation which emerged from the leadership campaign as a "rabble".
But the leader, who will pass the landmark on Monday, said: "They should recognise that I was elected with a very large mandate from a very wide variety of people from all parts of the movement.
"There is no imposition of any mob. What there is is a development of participatory democracy. The parliamentary party is a part of the party, a very important part, but it is not the totality of the Labour party."
He said: "I would encourage them to share their talents with all of us, not keep it to themselves. Some people are more difficult to reach than others. They shouldn't obsess about me."
Mr Corbyn has faced dissent at meetings of the Parliamentary Labour Party, which is profoundly split over his views on issues such as opposition to the renewal of Trident and air strikes in Syria.
He was scathing about the rapturous reception given to shadow foreign secretary Hilary Benn's speech in favour of the military action against Islamic State, credited with encouraging some of the dozens of Labour MPs to voted in favour, in defiance of the leader's stance.
"I did not agree with it. I was appalled that MPs should clap, shout and cheer when we were deciding to go and bomb somewhere. Parliament is supposed to be serious. It's not a place for jingoistic cheering."
Mr Benn has been tipped by some for the sack in a shake-up of the front team in the new year.
"There will be appointments when appointments are made," Mr Corbyn said when asked about a reshuffle.
He said predecessor Ed Miliband was "a great guy and a great friend" who he would work with "in any way he wants to work with me".
Complaining about the public airing of disagreements, he added : "We should hold shadow cabinet meetings in public. I think I'm the only one who doesn't leak."
Mr Corbyn told the HuffPost UK website that he recognised that he had made some mistakes and would make more.
"Decisions come to you and you have to take them. And I make mistakes like anybody else, I will make mistakes. And you have to reflect on it and you have to listen to people. That is the key," he said.
He accepted that he "obviously had not been clear" in expressing concern over armed police operating a shoot-to-kill policy, which sparked claims - which he denied - that he was opposed to shooting dead terrorists engaged in a Paris-style attack in the UK.
"I obviously had not been clear, that's one thing. It's issues like that you have to recognise that people are always looking for one word you say, not the whole sentence," he said.
He complained of "unbelievable" levels of hostility towards him in the media.
"Frankly some of it is just plain abuse," he said, but insisted he would stick to a long-term policy of not responding to personal attacks.
He said he seeks to spend no more than three and a half days at week at Westminster - insisting on keeping up his role as a constituency MP and touring the country.
"There is a sort of relentless demand on one, so every week Prime Minister's Question Time comes round, every week there's a whole lot of things that have to be done," he said.
"And it's balancing that with the need to not spend one's whole time in one's office, dealing with whatever crisis appears. I find if you are in an office, the crisis finds you. If you're not in the office, the crisis finds somebody else."