A candidate for Nigel Farage’s Brexit Party has quit in protest at the failure of another would-be MEP to apologise for previous support for the IRA.

Sally Bate, from Warrington, said she was unhappy with the position taken by Claire Fox, a former senior activist in the Revolutionary Communist Party (RCP), on the 1993 bombing of the Cheshire town.

An RCP newsletter at the time of the attack, which killed schoolboys Tim Parry and Johnathan Ball, stated that the party defended “the right of the Irish people to take whatever measures necessary in their struggle for freedom”.

Ms Fox – now director of the Institute of Ideas think tank – is top of the list of Brexit Party candidates for the North West, meaning she will be the first to claim any European Parliament seat which the group wins in the May 23 election. Ms Bate was listed seventh, giving her no realistic chance of election.

Tim’s father Colin Parry said that Ms Fox called him on Wednesday after he urged voters in the North West to reject her but did not offer any apology for her former views.

“I give some credit to Claire Fox for having the gumption to call me today,” tweeted Mr Parry late on Wednesday.

“But the fact that she repeatedly refused to disavow her comments supporting the IRA bombing which took Tim’s and Johnathan’s young lives proves she hasn’t changed her original views.”

Announcing her resignation from the Brexit Party, Ms Bate said: “I refer to the statement made by my fellow candidate Claire Fox about the position of her former party the Revolutionary Communist Party on the Warrington Bombing by the IRA in 1993.

“I am unhappy with Claire’s statement since she has not categorically condemned the violence inflicted by the IRA.

“I stand by Colin Parry and his family and all victims of the Warrington bomb and in view of Claire’s ambiguous position on the issue I cannot continue to stand beside her as a Brexit candidate and resign with immediate effect.”

In a statement, Ms Fox said she did not condone violence.

“Terrible things happened – mercifully a peaceful resolution has emerged following the Good Friday Agreement,” she said.

“I do not condone the use of violence.”

Brexit Party chairman Richard Tice said, “I’m very sorry that Sally Bate has decided to resign as a candidate.”

Heidi Allen, the leader of Remain-backing Change UK, welcomed Ms Bate’s move and called for Ms Fox to be dumped as a candidate.

“Well done to Sally Bate for a principled decision,” said Ms Allen.

“Claire Fox’s refusal to condemn the Warrington IRA bombing is totally unacceptable. Nigel Farage must remove her from the Brexit Party list. It is without question, that we all stand together with the victims of that atrocity.”

Dan Price, a Change UK candidate for the North West, said: “Nigel Farage has shown incredible ignorance in sending an IRA apologist up from London to stand in Warrington as a Brexit Party candidate. He’s badly misjudged the mood in our town.

“The fact that Claire Fox has rubbed salt in the wounds by phoning Colin Parry and repeatedly refused to disavow her comments supporting the IRA bombing in Warrington is a further reminder that she is not fit for public office.

“I’m afraid the mask is now slipping on Farage’s nasty new venture. There cannot be any room in British politics for people who justify killing children for ideological means.”