The defence secretary, Penny Mordaunt, has vowed to review Ministry of Defence internal guidance on the sharing with allies of intelligence derived from torture.

An MoD policy document, published following freedom of information requests by the Rendition Project and reported in the Times, stated that UK ministers could share information obtained from third parties where there was a serious risk of torture “if ministers agree that the potential benefits justify accepting the risk and the legal consequences that may follow”.

The document appeared to be at odds with the government’s official torture policy, known as the consolidated guidance, which states that Britain does not “participate in, solicit, encourage or condone the use of torture or cruel, inhuman or degrading treatment or punishment for any purpose”.

The MoD said its policy and activities complied with the consolidated guidance and said the Investigatory Powers Commissioner’s Office, the security watchdog, was satisfied with the MoD’s activities and standards in this area.

Speaking in parliament, Mordaunt said she would review the MoD policy document, but only once a review of the consolidated guidance, currently under way, was completed in the coming weeks.

“The UK government stands firmly against torture and does not participate in, solicit, encourage or condone the use of torture or cruel, inhumane or degrading treatment or punishment for any purpose,” said Mordaunt.

She said the MoD’s policy was in accordance with both domestic and international law, and was aligned with the government’s policy on sharing and receiving intelligence.

“The prime minister has asked [the investigatory powers commissioner] to review the government’s consolidated guidance and submit proposals for how it could be improved,” she said. “Once it has done so and the government has had a chance to consider them, and I anticipate that this will be a matter of weeks, the MoD will review its internal guidance and, as necessary, in the light of any updated guidance that is published.”

The shadow defence secretary, Nia Griffith, said the MoD had “discreetly rewritten government policy on torture”, describing the revelations as extremely concerning. “Today’s reports suggest that, according to the Ministry of Defence, torture is acceptable if – and I quote from the policy document – ministers agree that the potential benefits justify accepting the risk and the legal consequences that follow.”

She added: “The MoD has denied any wrongdoing, maintaining that the policy and activities in this area comply with the Cabinet Office’s consolidated guidance on torture. However, that guidance clearly sets out that in no circumstance will UK personnel ever take action amounting to torture.

“It further maintains that where the government cannot mitigate the serious risk of torture at the hands of [a] third party, the presumption would be that we will not proceed.”

The former Brexit secretary David Davis said: “Our most senior living soldier, Field Marshal Lord Guthrie, said 10 years ago: ‘Torture is illegal. It is a crime in both peace and war that no, I repeat no, exceptional circumstances can permit. We need to distinguish ourselves from our enemies. We must not, in the false name of moral equivalence, degrade ourselves to their level.’ And he was right.

“The prohibition of torture is one of our few absolute incontrovertible rights. There can never be a reason or justification for it and, what’s more, it doesn’t work. It leads to bad intelligence and bad decisions.”

During her first defence questions in parliament since being promoted after the sacking of Gavin Williamson, Mordaunt was repeatedly asked about plans to introduce a historical prosecutions amnesty for most military veterans. MPs were told there would be a written ministerial statement on the subject on Tuesday.

The proposals would introduce a presumption against prosecution for offences committed more than 10 years ago, covering wars in Iraq and Afghanistan. While the proposals do not currently cover those who served during the Troubles in Northern Ireland, Mordaunt said last week that she wanted them to.