SENIOR figures within Labour are calling on the Electoral Commission to investigate a controversial group set up to oust Jeremy Corbyn as party leader. Prominent critics have labelled Saving Labour as a shadowy and anonymous organisation whose source of funding is unknown.

Labour’s UK campaigns and elections chair Jon Trickett, former London mayor Ken Livingstone and Fire Brigades Union (FBU) leader Matt Wrack, were unanimous in calling for the commission to probe the financing of the organisation which “sprung up overnight”.

Read more: Corbyn opponents trying to destroy Labour Party, John McDonnell claims

Saving Labour has taken out prominent media advertisements against Corbyn and won endorsements from celebrities like Harry Potter author JK Rowling, former EastEnders actor Ross Kemp and comic Robert Webb.

It is reported that former Labour MP Reg Race, now a medical entrepreneur, set up Saving Labour, which claims on its website that “Jeremy Corbyn has alienated almost all his colleagues in Parliament, has failed to set any kind of policy agenda and cannot meet the profound challenges of the future”.

However, Trickett, who is Labour’s Shadow Business Secretary, said that as the group was seeking to influence who is the UK’s opposition leader that it had a “series of questions” to answer about where it got its cash from and who was behind it.

The pro-Corbyn group Momentum has already been approached by the Electoral Commission after Blairite Labour MP Emma Reynolds asked for its finances to be investigated. Momentum had claimed to be receiving £11,000 a day in the period after the majority of Labour MPs passed a no confidence vote in Corbyn, prompting Reynolds to write to the commission.

Read more: Kezia Dugdale will urge US to heed Brexit lessons to prevent Donald Trump presidency

But the commission replied that the “absence of credible evidence” to suggest there had been a breach of the legislation governing political donations meant they would not take any action. Trickett said that Saving Labour should now be subject to the same rules on “transparency” from the commission that state that membership political groups, such as Momentum, must check any donations above £500 come from legitimate sources and must declare any donations above £7,500. The Labour Shadow Cabinet minister said that the organisation “has clearly got significant funds”, when asked about the glossy ads the group has taken out in national newspapers and the campaign video fronted by former EastEnders star Kemp.

Trickett, the MP for Hemsworth in West Yorkshire, said: “We have to know who is behind it as it’s sprung up overnight. Is it an organisation that’s open to all party members or can anyone join and how is it funded? These are all questions that need to be answered.”

In a call to the Electoral Commission to step-in, Trickett said: “There is a regulatory body and if an anonymous group is seeking to influence the party’s business and who leads it they should consider this. They should look at it.”

Trickett said that he would consider formally requesting that the Electoral Commission looks at the finances and openness of Saving Labour, along similar lines to the move against Momentum from his fellow MP Reynolds, who quit as a shadow minister last year following Corbyn’s election as leader.

Meanwhile, the Spinwatch website claimed that Saving Labour was entered in the UK’s data protection register as an address also listed at Companies House as the correspondence address of Denys Alan Reg Race, a director of Quality Health Ltd.

Read more: Scottish Labour leadership rift deepens

Race, who was a Labour MP from 1979 to 1983, set up Quality Health, which carries out staff and patient surveys for the NHS.

He failed in his bid to return to the Commons in 2001, when he was defeated by the Liberal Democrats in the Chesterfield constituency, which Tony Benn had stood down from that year. The call for transparency was also backed by Livingstone who said Saving Labour had to clear up concerns that it was funded by corporate interests that wanted to push the party to the right. When asked about whether the Electoral Commission should probe the group, the former Greater London Council leader and Labour MP, said “absolutely”.

Livingstone highlighted the funding former Sainsbury’s boss David Sainsbury had given to the Blairite pressure group Progress, as well as the SDP, which split from Labour in the early 1980s. He said: “I’m sure there’s big money behind it and I’m sure they will try to keep it hidden.

“My broad view is that we should ban any corporate organisations funding politics and we shouldn’t allow these organisations to have more influence than an elected MP. For years Progress was funded by David Sainsbury, who was also one of the biggest funders of the SDP.”

FBU general secretary Wrack said he would consider asking the commission to look into the outfit’s funding, suggesting Corbyn’s opponents had turned the leadership election into an increasingly bitter contest by seeking to link the leader to bullying allegations. Owen Smith, Corbyn’s leadership opponent, accused the party leader of not doing enough to clamp down on “intolerance and misogyny” after over 40 female Labour MPs signed a letter highlighting such claims.

However, Wrack responded: “It’s turning into a pretty dirty campaign and some of these claims are pretty terrible as they seem to be just throwing mud at Jeremy and hoping that some of it will stick.”

On Saving Labour he added: “Political funding should be open and if there are big wealthy donors giving to it (Saving Labour), then we have a right to know.”

The Electoral Commission said it would look into any complaints it receives about the conduct of political campaigns in line with its rules.

A spokesperson said: “There are rules that certain organisations must follow in relation to donations and loans that they receive in connection with their political activities, including reporting any donations or loans of more than £7,500 to the Commission. Any allegations that there has been a breach of these rules which are supported by evidence will be considered by the commission in line with our usual enforcement procedures.”

A Saving Labour statement said that the group is "a grassroots initiative to sign up those who want a strong, credible and competent Labour Party to vote in the leadership election."

It added: "Saving Labour will make all the necessary declarations to the proper authorities at the correct time, including those relating to our funding. For now we are concentrating on signing up affiliated supporters in trade unions to vote."