Former Cabinet minister Sir Vince Cable has accused the Ministry of Defence of "seriously misleading" him when he signed off a Saudi arms deal.
The Liberal Democrat said he was given specific assurances about the checks that would be made on the use of British-made missiles when he was responsible for authorising export licences.
Sir Vince insists that the MoD told him there would be oversight of targeting, which is why he agreed to sign the documents for a consignment of laser-guided Paveway IV missiles.
The former business secretary said he deemed the promises vital to minimising the risk of civilian casualties in Saudi Arabia's controversial Yemen bombing campaign.
According to the Guardian, the MoD has no military personnel in the "targeting chain" and has denied ever offering the assurances to Sir Vince.
But the former Cabinet minister said: "That is categorically contrary to what I was told was going to happen. If what they are now saying (is) I was not offered oversight on an equivalent level to the Americans, and that this would involve oversight of targeting, then I was seriously misled. That is total fabrication because that was very specifically stated. That is not something that I would have made up."
He added: "My very clear understanding was that the equipment would be supplied to Saudi Arabia on the very clear basis that British personnel would have oversight of what the Saudi air force was doing, on the same basis as the Americans."
Sources told the newspaper that the MoD was "desperate" to get the licences signed off because the Saudis were putting "enormous pressure" on the Government.
The MoD told the Guardian while it had agreed to "increase oversight of the targeting process" last year, that did not involve oversight of targeting at any stage.
"British personnel are not involved in carrying out strikes, directing or conducting operations in Yemen or selecting targets and are not involved in the Saudi targeting decision-making process," a spokesman said.