Home secretary promises action to prevent any repeat of council and police failures but has still to name new head of inquiry

Theresa May has described the failures of police and council agencies in Rotherham to deal with child sex abuse as a complete dereliction of duty.

In a strongly worded statement, the home secretary told MPs that "institutionalised political correctness" had contributed to the authorities turning a blind eye to the abuse of at least 1,400 in Rotherham between 1997 to 2013.

"Like the rest of this House, I was appalled to read about these victims and the horrific experiences to which they were subjected," she said. "Many also suffered the injustice of seeing their cries for help ignored and the perpetrators not yet brought to justice. There can be no excuse for that."

May, who was responding to an urgent question by Yvette Cooper, the shadow home secretary, said she would meet Prof Alexis Jay – who wrote last week's damning report into the Rotherham child sex abuse scandal – and chair meetings with other ministers, to see what could be done to prevent any repeats.

May said Eric Pickles, the communities secretary, was minded to order an investigation into Rotherham, and into whether it is complying with its best practice duty.

She said: "I am clear that cultural concerns – both the fear of being seen as racist, and the frankly disdainful attitude to some of our most vulnerable children – must never stand in the way of child protection. We know that child sexual exploitation happens in all communities. There is no excuse for it in any of them. And there is never any excuse for failing to bring its perpetrators to justice."

Cooper agreed that race, ethnicity or community relations should not be used as an excuse not to investigate and punish sex offenders. May, however, did not name a new chair to the overarching inquiry into the authorities' handling of child sex abuse over several decades.

The inquiry was announced in July, only for its chair, Lady Butler-Sloss, to step down a few days later over a possible conflict of interest.

Meanwhile, South Yorkshire police have announced a "fully independent investigation" into the force's handling of the Rotherham abuses.

But some legal experts questioned whether the inquiry could be fully independent.

"One police force investigating another police force will not bring justice to victims of Rotherham," said Jocelyn Cockburn, the solicitor of murdered Stephen Lawrence's father, Neville. "The police have proven to be thoroughly incapable of investigating themselves, and each other, on many occasions. I fear another whitewash will ensue. Quite simply, the police should not investigate the police in a matter of this seriousness."

The Labour party has suspended four Rotherham councillors. Roger Stone, who has already resigned as council leader, Gwendoline Ann Russell, Jahangir Akhtar and Shaukat Ali have been suspended pending investigation after Ed Miliband said last week that large numbers of young people in Rotherham were systematically abused and let down by those who should have protected them. In addition, two former members of the party, Shaun Wright and Maurice Kirk, will require national executive committee approval should they want to rejoin the party.

Wright, the current police and crime commissioner for South Yorkshire, was in charge of children's services in Rotherham for five years before taking up his current post, and is resisting fierce pressure to step down. He has agreed to give evidence before the home affairs select committee chaired by Keith Vaz.

Vaz said: "I have spoken to Commissioner Wright this morning and informed him that the committee will want him to give evidence as part of our inquiry, and he has agreed to do so."

The shadow education secretary, Tristram Hunt, told Sky News: "We've had a week to look at Prof Jay's report and investigate those members of our party, the Labour party, who were in positions of power and authority and who we think failed to act appropriately when they were in those positions of authority."

In announcing an investigation of the police's handling of the abuse of children in Rotherham, Ch Con David Crompton said: "A fully independent and impartial investigation is required to ensure that people have confidence that organisations or any individuals will be investigated fairly, rigorously and with complete impartiality."

The investigation will examine the role of both the police and council and address any wrongdoings or failings, which will allow "appropriate action to be taken". He added: "We must give victims the confidence to come forward in the knowledge that all agencies will listen, will act, provide appropriate support, and relentlessly pursue those who offend against our young people."

The latest moves follow a BBC Panorama documentary screened on Monday night in which a Home Office official who investigated the sexual exploitation of children in Rotherham accused the council of being involved in the unauthorised removal of information from her office.

Her report in 2002 suggested there were then more than 270 victims of the scandal, which was finally exposed last week. She told Panorama she had sent her report to both the council and the Home Office on a Friday, but when she returned on Monday she found her office had been raided.

"They'd gained access to the office and taken my data, so out of the number of filing cabinets there was one drawer emptied and it was emptied of my data. It had to be an employee of the council," she said.

The Home Office researcher, who was not named by Panorama, also said she had been accused of being insensitive when she told one official that most of the perpetrators were from Rotherham's Pakistani community.