Jeremy Corbyn has advised Sir Keir Starmer to stop trying to “diss” his time as Labour leader and instead embrace nationalising key services.

Mr Corbyn indicated that, if he is re-elected as Independent MP for Islington North, he would offer support to a Labour government but only when it does “something good”, such as returning Royal Mail and the railways to public ownership.

He added that his successor as Labour leader seems to think “forgetting the past and pretending it never happened is somehow going to make you strong”.

Sir Keir has spent much of the campaign trying to emphasise how the party has changed, as the Conservatives focus on his previous backing for left-wing policies as a member of Mr Corbyn’s shadow cabinet.

Mr Corbyn, 75, was greeted by cheers and chants of “Oh Jeremy Corbyn” from supporters as he left Islington Town Hall on Wednesday after handing in his nomination papers to officially stand at the General Election on July 4.

He is seeking to extend his more than 40-year tenure as MP for Islington North as an Independent after Sir Keir banned him from standing for Labour as part of his efforts to “tear antisemitism out of our party by the roots”.

Mr Corbyn was suspended by Labour in 2020 after he refused to fully accept the Equality and Human Rights Commission’s findings that the party broke equality law when he was in charge and said antisemitism had been “dramatically overstated for political reasons”.

Speaking on the town hall steps, he said: “We will take this campaign to every door in Islington North and I’m so grateful to all of you who, in a week, have come forward and done so much work already.

“Do you know what? We’re going to win this thing.”

He added: “When the new government does something good, yes, I’ll agree and support them – public ownership of Royal Mail, public ownership of our railway system, public ownership of our water.

“Regulation of the privatised utilities has not worked and never will work. Bring them back into public ownership.”

Mr Corbyn also stressed the need for “opposition to racism in absolutely any form whatsoever”.

Asked about Sir Keir’s insistence that Labour has changed, Mr Corbyn told BBC London: “He was very happy to be in the shadow cabinet through all that time, he was very happy to support the 2017 and 2019 manifestos, and was very happy to campaign to be leader on the basis of defending the policies of those two manifestos.

“So I think something has changed and it’s not me and it’s not those manifestos.”

He added: “I don’t think there’s any need for him to diss the past or diss his own involvement in it.

“When we came up to the 2019 election, the manifesto, policies and the strategies were agreed unanimously by both the shadow cabinet and the National Executive.”

Asked why Sir Keir is dissing the Corbyn era, Mr Corbyn told reporters: “He seems to think that forgetting the past and pretending it never happened is somehow going to make you strong.”

He added: “You can’t just diss the past – you’ve got to understand why things happen.”

Mr Corbyn said he is “pretty sure” Sir Keir will be the next prime minister, but he also accused Labour of “trying to get rid of as many left candidates as they can” and described the situation as “deplorable”.

Sir Keir, asked whether he could see why Mr Corbyn thought it was “disrespectful” that he had “disowned” much of the 2019 Labour manifesto, told reporters at Portsmouth Historic Dockyard: “I have as my focus the voters, not Jeremy Corbyn.

“And the voters in 2019 rejected the Labour Party very badly, the worst result since 1935.

“I think if you get rejected that badly you don’t go back to the voters and say we were right, what were you doing? You change your Labour Party and that’s why I’ve changed the Labour Party and in particular made it a party that always puts country first and party second.”

Arsenal fan Mr Corbyn was also asked by the PA news agency how trying to win Islington North as an Independent would rank in comparison to previous exploits by the Gunners, including the Invincibles team managed by Arsene Wenger and Michael Thomas’s last-minute winner to help them beat Liverpool to the title in 1989.

Mr Corbyn replied: “Remember that song – 2-0 down with 20 minutes to go, Viera stepped up for a throw.

“Come on Arsenal – and we won it.”

Comedian and actor Rob Delaney supported Mr Corbyn at the town hall on Wednesday, and said of his chances of being elected: “They’re going to be pretty good. Everybody knows him, it’s so hard to compete.

“You can’t get a consultancy firm to give you what he has, you can’t replicate what he’s done in 40 years overnight.”