Boris Johnson has attempted to defend his meeting with former Russian spy Alexander Lebedev insisting "no Government business was discussed as far as I'm aware".
The outgoing Prime Minister reluctantly admitted to MPs earlier this month that he met the Russian oligarch in Italy on April 28 2018 without officials present.
He visited Lebedev's castle in Perugia while he was Foreign Secretary, for a weekend-long party after attending a Nato foreign ministers' meeting in Brussels in which he had discussed Russia and security.
Writing back to the Commons Liaison Committee who quizzed him on this meeting on July 6 in a bid to provide further detail on the meeting, Mr Johnson said: "At this social event, I also met Evgeny Lebedev’s father.
“This was not a formal meeting, nor something that was pre-arranged.
“Officials were aware in advance that I was attending the social event."
He added: "If a minister meets an external organisation or individual and finds themselves discussing official business without an official present - any significant content should be passed back to the department after the event.
"That was not necessary in this case. As far as I am aware, no Government business was discussed."
Labour's deputy leader Angela Rayner has slammed Mr Johnson's response, claiming he "has something to hide".
"The Prime Minister claims the meeting wasn’t pre-arranged and yet also says officials had been made aware in advance, but he apparently still can’t recall whether he discussed government business or not.
"He has failed to answer whether a private phone call with Russian Foreign Minister Sergei Lavrov had been arranged or explain the presence of an undeclared and unidentified guest.
"As Foreign Secretary, Boris Johnson ’s carelessness with words put people in danger. Every day he clings to office, there is new evidence of the risk to national security he poses."
Mr Johnson used the rest of his written reply to defend his response to the Salisbury poisonings and to highlight actions taken against Russia.
He even claimed “historic returns” up to 2016 from Labour about their meetings with senior media executives showed “considerable engagement by the shadow cabinet with Evgeny Lebedev and attendance at his social events”.
The Commons Intelligence and Security Committee has scrutinised Lebedev's appointment to the House of Lords.
The Government has refused to publish intelligence advice relating to a peerage handed to Russian-born businessman Evgeny Lebedev - a friend of Boris Johnson.
MPs backed a Labour motion seeking to force ministers to publish documents about the Prime Minister’s involvement in his appointment to the House of Lords.
But after missing the deadline to publish the documents last month, the Government has published a handful of heavily redacted papers.
And despite being ordered by Parliament to release the documents - a minister said in a lengthy statement that they had to consider whether it was in the "public interest" to do so.
They released the blank form Lord Lebedev was required to fill in the by House of Lords Appointments Commission, the public citation announcing his appointment, a list of the other peerages awarded at the same time, and a letter congratulating him on his appointment.
