A Windrush campaigner who launched a fundraiser for Jason Arday’s family has said the outpouring of support shows “Britain still cares”.

Arday, who was found dead on Friday, had resigned the previous week from his post as professor of sociology of education at the University of Cambridge after allegations of plagiarism were made against him.

A vigil organised by the group Stand Up to Racism will be held on the steps of the National Gallery in Trafalgar Square, central London, at 6pm on Monday.

Cambridge’s chancellor, Chris Smith, has broken his silence over the controversy and described a “racist feeding frenzy” around the academic’s death.

On Saturday, Sir Patrick Vernon, who played a leading role in the successful campaign to establish a national Windrush Day, set up a GoFundMe crowdfunding page, which has collected more than £150,000.

He told the Press Association the outpouring of support shows that the public “still cares” and felt “angry”.

“Britain still cares – people, black, white, brown, care and feel angry about the situation,” he said. “People want to support the family. There’s lots of speculation about how much money Jason has or doesn’t have – that’s not the point. The fact is, people want to support the family because he’s dead, he’s died and he has a young family.

“He has parents and he has a family that he has supported, and people want to support the family.”

Vernon was one of several public figures, including the Green party leader, Zack Polanski, and the crossbench peer Simon Woolley, to sign an open letter supporting Arday as he faced mounting scrutiny from the press. Vernon said the treatment of Arday raised questions around press regulation, the University of Cambridge and the “state of race relations in Britain today”.

Before Arday’s death, Cambridge said it would investigate the circumstances around his “appointment and tenure” and the findings would feed into a review of the process for appointing senior roles.

It is understood the university does not feel it is right to make a decision on whether to proceed with its investigation while Arday’s family are grieving.

In a statement released on Monday, Smith said: “I do believe it is possible to hold to two principles at the same time: to believe in the importance of academic integrity, and where criticisms of plagiarism arise, about any academic, whoever they are, ensure that they are rigorously investigated. And also to refuse to join in a racist feeding frenzy over a particular academic.”

Downing Street declined to say “at this stage” whether Andy Burnham was considering an inquiry over the death of Arday.