James Heappey, who was armed forces minister at the time the data breach came to light, said claims he had backed a “new entitlement” for people affected by the breach but not eligible for other schemes were “untrue”.

His comments on social media on Thursday appeared to contradict those of former immigration minister Robert Jenrick, who said he and former home secretary Suella Braverman had “strongly opposed” plans for the Afghan Response Route in “internal meetings”.

But Mr Heappey, himself a former Army officer who served in Afghanistan, said the cross-government committee responsible for the policy “tried to extend entitlements by the smallest number possible”.

He said: “This was led by legal advice & I don’t recall fierce opposition. There was frustrated resignation that it was necessary.”

Mr Heappey did, however, recall “rancorous” meetings in which departments “fought fiercely for their priorities and/or to avoid unresourced responsibility”.

He also denied that a new “secret route” was not under consideration at the time he resigned as armed forces minister in March 2024.

The data breach, which saw a defence official release the details of nearly 19,000 people seeking to flee Kabul in 2022, became public on Tuesday after an unprecedented superinjunction banning reporting of the breach was lifted.

Since then, Conservative former ministers have sought to distance themselves from the handling of the breach and the subsequent creation of a secret relocation scheme, the Afghanistan Response Route, in April 2024.

Along with Mr Jenrick’s claims of having opposed the route prior to his resignation in December 2023, Ms Braverman herself has said there is “much more that needs to be said about the conduct of the MoD (Ministry of Defence), both ministers and officials”.

Former veterans minister Johnny Mercer claimed he had “receipts” regarding the previous government’s actions in relation to Kabul, and has described the handling of the breach as “farcical”.

Sir Ben Wallace, who applied for the initial injunction as defence secretary, has said he makes “no apology” for doing so, saying it was motivated by the need to protect people in Afghanistan whose safety was at risk.

Mr Heappey backed up his former boss, saying the superinjunction was “needed” to protect people from “mortal danger”.

He said: “The intelligence assessment was clear: if the Taliban got their hands on the list, violent and even lethal reprisal was likely.”

Mr Heappey added that, although a review by retired civil servant Paul Rimmer found there was now little threat to those on the list as a result of the breach, this did not mean the threat had never existed.

He also sought to defend the individual responsible for the leak, saying they had been “incredibly dedicated to those we served with in Afghanistan”.

Grant Shapps, who was defence secretary by the time the superinjunction was granted, has not yet publicly commented on the revelations.

The data breach saw a dataset of 18,714 people who applied for the Afghan Relocations and Assistance Policy (Arap) scheme released in February 2022 by a defence official who emailed a file outside authorised government systems.

Defence sources have said that details of MI6 spies, SAS and special forces personnel were included in the spreadsheet, after they had endorsed Afghans who had applied to be brought to the UK.

The Ministry of Defence only became aware of the blunder when excerpts from the dataset were posted anonymously on a Facebook group in August 2023, and a super-injunction was granted at the High Court in an attempt to prevent the Taliban from finding out about the leak.

The leak also led to the creation of the secret Afghanistan Response Route, which is understood to have cost about £400 million so far, with a projected final cost of about £850 million.

A total of about 6,900 people are expected to be relocated by the end of the scheme.

The official responsible for the email error was moved to a new role but not sacked.

The superinjunction was in place for almost two years, covering Labour and Conservative governments.

Tory leader Kemi Badenoch has apologised on behalf of the Conservatives for the leak, telling LBC: “On behalf of the government and on behalf of the British people, yes, because somebody made a terrible mistake and names were put out there… and we are sorry for that.”

Meanwhile, Parliament’s Intelligence and Security Committee has demanded to see intelligence assessments relating to the data breach “immediately” as MPs and peers begin inquiries over the incident.

The Commons Defence Committee has also indicated it will call former ministers to give evidence on the breach, and Mr Heappey said he would be “happy to contribute” to the committee’s inquiry.