Jeremy Corbyn has hinted he would be able to forget the criticism of fellow Labour MPs if he were to win the leadership race, following a rally in Derby where he reiterated his commitment to the full nationalisation of rail services.

Speaking to reporters after his speech on Tuesday, Corbyn was asked about comments by the Derby South MP, Margaret Beckett, who said many people had joined the party purely to support him.

“We have had examples of people saying: ‘I want to join the Labour party because of Jeremy, but of course if he ceases to be the leader I shall leave,’” she told the BBC. “Those are not members of the Labour party, those are members of a fan club.”

Corbyn said he was happy to continue to work with Beckett, and that the pair had recently spoken about nuclear disarmament. “People say a lot of things and I think I’ve got the ability to forget those things,” he said.

He said he was keen to move on after the leadership result is announced on 24 September, but said he recognised that winning would not necessarily mean an end to the criticism. “Unfortunately that is not in my hands,” he said. “I hope at the end of this leadership contest everyone will recognise we’ve had the debate.

“I’ve been nominated by 300-odd constituency Labour parties. There is support here for a different way of doing politics and I hope all my colleagues in parliament will reflect on that and reflect on how we can work together.”

Corbyn has spent Tuesday campaigning on transport, meeting commuters at London Bridge station during a protest by unions against the beleaguered Southern rail, followed by campaign rallies in Derby and Matlock.

Speaking in Derby, Corbyn he it was the 21st speech of his leadership campaign, which aimed to visit every major city and town in the UK. He renewed his pledge to renationalise the railways, which he said would mean bringing each franchise back into public ownership when it came up for renewal.

“The costs of rail travel will be borne by public as a whole and profits will go to the public,” he said. “Profits from the east coast mainline are now going to Virgin.

“This campaign is about the election of one person to be leader of the party. But put it this way, it’s a campaign about the kind of country we want to live in and the place we want to play in the world.

“Our programme is about social justice, opportunities for all and a sustainable economy, but it is also about how we do our politics. Do we allow an elite to decide what the politics should be, what the policies are … or is it about the participation of the hundreds of thousands who are now part of our party and our movement??”

His campaign says passengers could see savings of up to 10%, though critics have said in practice that it would take several years for any savings to trickle down to passengers.

Corbyn also announced what his team said was a plan to extend public control over bus networks, allowing local authorities to have franchising power and establish municipal bus companies.

His leadership rival Owen Smith’s campaign said on Tuesday that the policies the Corbyn campaign had announced were not new. Rail renationalisation was agreed by the last shadow cabinet, and Smith’s campaign also said the proposals on bus networks had been agreed in 2012 when Maria Eagle was transport secretary.

“There is nothing new in what Jeremy is saying. He is simply rehashing existing Labour party policy,” a spokesman for the Smith campaign said. “Owen has pledged to go further to improve our rail and bus networks by promising a £200bn ‘British New Deal’ to invest in things like transport services to help get the country moving again.”