Ukip faces the prospect of further damaging infighting after its leader, Gerard Batten, made the far-right activist Tommy Robinson one of his advisers, prompting outrage from senior members and a call from Nigel Farage to depose Batten.

Just nine months after the party ousted Henry Bolton as leader over offensive comments made by his girlfriend, Farage said he would write to Ukip’s national executive committee (NEC) to seek a no-confidence vote in Batten.

One member of the NEC has since announced he backs the move.

Farage, Ukip’s most successful leader who remains hugely popular in the party, condemned Batten’s decision to make Robinson, whose real name is Stephen Yaxley-Lennon, an adviser on grooming gangs and prisons.

“Gerard Batten has got this sort of fixation with Tommy Robinson and discussing Islam, and dragging Ukip in a direction of effectively being sort of a street activist party right at the moment when we have a betrayal of Brexit going on by both the Conservative and Labour parties, where Ukip’s got potential reach out among the electorate, the highest it’s ever been,” he said.

“It goes against all the things I did as leader to say we will talk about immigration, we will talk about the extreme forms of Islam [and] we’ll do it as a non-racist, non-sectarian party. This blows a hole in all of that.”

Farage added: “He [Batten] doesn’t have the support of the party to do this. Even a poll of party members shows that his issues are very low down on our list of priorities, so I’m going to fight, try and save it [Ukip], but if it continues in this direction, electorally it is finished.”

Nigel Farage remains a hugely popular figure within Ukip. Photograph: Aaron Chown/PA

Batten has long been open about his anti-Islam views, calling the religion a “death cult” and suggesting that UK Muslims should be asked to sign a declaration renouncing elements of the Qur’an.

Since taking over from Bolton in February, initially on a one-year term, Batten has sought to push Ukip in a more hard-right direction, alarming many in the party and prompting the departure of a series of MEPs and other officials.

The changes have been both in policy – Batten has proposed a halt on immigration from Islamic countries and separate jails for Muslim prisoners – and in his embracement of Robinson, the founder of the English Defence League (EDL), who he has compared to Mahatma Gandhi and Nelson Mandela.

Batten has sought to change party rules that banned former members of far-right groups such as the EDL from joining, but has been frustrated by the NEC. This week the committee announced that Batten had been told to wait until after Brexit to seek a rule change.

Ben Walker, an NEC member, said Batten wanted “Ukip to be a vehicle to attack Islam”, and that this focus had lost the party support and members.

Walker added that he supported Farage’s call, saying: “I ask Gerard to step aside and allow the party to be led in the interim by someone else.”

Another senior member, the MEP Patrick O’Flynn, tweeted that he shared Farage’s worries about Robinson, “and so do the vast majority of longstanding Ukip members that I know”. He added: “This issue is coming to a head very quickly now.”

In Batten’s response to Farage, the Ukip leader attacked the NEC, tweeting: “This is the same NEC Nigel described as ‘low grade people’ and a ‘swamp that needed to be drained’.”

Another drawn-out fight for control could be hugely damaging to Ukip, which has plummeted in the polls and is already on its fourth permanent leader since Farage stepped down in 2016.

Robinson has convictions for assault, drug and public order offences, and has been jailed for mortgage fraud and for using someone else’s passport to travel to the US.

He has sought to reinvent himself as a “campaigner” against Muslim gangs who groom girls for sex, which has attracted him a large and fervent audience. He is awaiting a decision on a contempt of court retrial, after he was jailed for livestreaming videos to Facebook from outside a grooming gang case.

Critics of Robinson’s actions describe him as an opportunist who has used the grooming issue to promote a more general far-right, anti-Islam agenda and push his personal brand.