An Islington MP has waded into the debate over an alleged police campaign to “smear” murder victim Stephen Lawrence’s family.

Jeremy Corbyn, MP for Islingbton North, told the House of Commons on Monday “heads do roll” at a high level of Scotland Yard and no credibility or confidence in policing unless an inquiry “really does get to the bottom of it”.

He spoke after undercover officer Peter Francis said he was instructed in 1993 to find information that could discredit the Lawrence family. Stephen Lawrence was stabbed to death by white youths in 1993 – it took 18 years to bring his killers to justice, leading to an enquiry led Sir William Macpherson which accused the the met of being “institutionally racist”.

Mr Corbyn said: “It’s something beyond disgusting that when many of us thought that Macpherson was a moving-on stage in the whole area of public policy in relation to the black community and the policing, that we find out that there were whole elements of the Metropolitan Police that had not moved on at all and indeed were busy smearing and obstructing justice in exactly the way they had beforehand.”

He added: “It’s also very clear that during the undercover operations used against the Lawrence family and in the McLibel case and in a number of other cases, senior officers in Scotland Yard must have known who was doing what, must have known of the disreputable personal behaviour of these people, and must still know about it.

“And so I hope that this inquiry is not restricted within the police force but in the words of Mr Efford is open and public and that heads do roll at a high level in Scotland Yard for those that have covered up the truth allowed smearing to go on and injustice to go on for a very long time.

“Otherwise there is no credibility in policing, there is no public confidence in policing unless this inquiry really does get to the bottom of it.”