Inquiry chair Sir Charles Haddon-Cave had repeatedly called on Johnny Mercer to name those who told him about the alleged killings by British troops, with the former Tory MP possibly facing jail if he does not comply.

But Mr Mercer, who is a former army officer, repeatedly refused to reveal the "multiple officers" who he claimed told him about allegations of murder and a cover-up while he was a backbench MP.

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A statement from the inquiry released on Thursday said Mr Mercer had "provided further information in response to the section 21 notice [threatening action] and agreed to assist the inquiry further", adding: "The inquiry team will be taking this forward."

However, in a tweet, Mr Mercer said he had still not revealed the names, saying while he "noted" the inquiry's statement, his "position remains unchanged from the beginning of the year".

Mr Mercer, who lost his seat at the general election, added: "I will always do all I can to assist this important inquiry. I will not betray those I served with who have confided in me, whatever the cost."

He added: "As I have repeatedly stated, it remains entirely inappropriate to name those who confided in me without their consent.

"For the avoidance of doubt: I have not and I will not. I will always assist the inquiry (outside of those parameters).

"This process has placed an unacceptable strain on me and my family. I am no longer a public figure; I will not be commenting further."

The Afghanistan Inquiry was set up by the Conservative government in 2023 to investigate extrajudicial killings that allegedly took place during the war in the country between 2010 and 2013.

It is examining whether a special forces unit, known as UKSF1, had a policy of executing males of "fighting age" who posed no threat in Afghanistan in those years.

Afghan families have accused UK special forces of conducting a "campaign of murder" against civilians, and that senior officers and personnel at the Ministry of Defence "sought to prevent adequate investigation".

The row over the names has been rolling on for months, with Mr Mercer first telling the inquiry - which protects witnesses from prosecution for breaches of the Official Secrets Act or for repeated failure to report misconduct - in February about what he had been told by officers previously.

After a series of orders to handover the names, Sir Charles set a final deadline of today, saying Mr Mercer could pass them on "privately and in strict confidence" and the inquiry would "protect the identities of confidential contacts", as well as protecting them from "risk of prosecution".

However, Mr Mercer had said he "gave [his] word to junior personnel who approached me" about the killings that he would not reveal their identities, and he intended to "keep it".