A Conservative party vice chairman is to apologise to Jeremy Corbyn for making false claims about links with communist spies, the Labour Party has said.
Ben Bradley was threatened with legal action after making the claims about Mr Corbyn on social media earlier this week.
The Tory MP’s tweet followed allegations about Mr Corbyn’s contact with a Czech intelligence agent in 1980s.
Mr Bradley apologised “unreservedly” for the message on Saturday, and agreed to never repeat the claims, according to statements released by the Labour Party on Saturday.
He will make a donation to a homeless charity and a food bank in his constituency, and meet the opposition leader's legal costs, the party said.
Better late than never from Conservative MP Ben Bradley. pic.twitter.com/FloV2j5FH3— Tom Watson (@tom_watson) February 24, 2018
Labour said Mr Bradley has agreed to tweet an apology that says: "On 19 February 2018 I made a seriously defamatory statement on my Twitter account, 'Ben Bradley MP (@bbradleymp)', about Jeremy Corbyn, alleging he sold British secrets to communist spies.
"I have since deleted the defamatory tweet. I have agreed to pay an undisclosed substantial sum of money to a charity of his choice, and I will also pay his legal costs.
"I fully accept that my statement was wholly untrue and false. I accept that I caused distress and upset to Jeremy Corbyn by my untrue and false allegations, suggesting he had betrayed his country by collaborating with foreign spies.
"I am very sorry for publishing this untrue and false statement and I have no hesitation in offering my unreserved and unconditional apology to Jeremy Corbyn for the distress I have caused him."
The written apology has been shared widely online, with Labour party politicians including Tom Watson tweeting the message.
Mr Bradley was promoted in Theresa May's January reshuffle, but quickly became embroiled in controversy after it emerged that he had suggested benefit claimants should have vasectomies.
Labour said it would not let "dangerous lies" about Mr Corbyn go unchallenged.
A spokesman for the leader said: "We are pleased Ben Bradley has admitted what he said was entirely untrue and apologised, and that charities in Mansfield will benefit.
"Following the botched smear campaign against Jeremy, this case shows we are not going to let dangerous lies go unchallenged."
It comes after a former spy chief insisted Mr Corbyn did have "questions to answer" over his Cold War links.
Sir Richard Dearlove said the Labour leader should have "taken care to avoid" meeting a Czechoslovakian agent and cannot just "laugh off" the claims.
The ex-MI6 boss said holding only a couple of meetings with Jan Sarkocy would amount to "stupidity", but if the spy's claims that many more took place were true then "this affair takes on a completely different aspect".
Labour said Sir Richard should not be "trying to give credence to these entirely false and ridiculous smears".
Mr Sarkocy, a former agent of the Czech StB intelligence agency, has been described as a fantasist by Mr Corbyn's allies.
But Sir Richard, who was "C" at the Secret Intelligence Service, said the agent could not be easily dismissed.
The "discussion I have had with friends close to the current Czech intelligence community" suggests otherwise, he told The Daily Telegraph.
Sir Richard, who was posted to Communist Czechoslovakia, said "everything I learned about the way the StB operated tells me that these accusations should be taken seriously".
Mr Corbyn's spokesman has previously challenged records of supposed meetings between the then Labour backbencher and Mr Sarkocy.
The Labour leader recalled speaking to a diplomat from the then communist country in 1986, as one of many meetings with ambassadors, politicians, activists and dissidents from "the majority of countries in the world", said the spokesman.
But another meeting with the same man was recorded in StB files as taking place the following year in the House of Commons, on a Saturday when the Labour MP's own diaries record he was attending a conference in Chesterfield.
A spokesman for Mr Corbyn said: "Richard Dearlove, who as head of MI6 was involved in the infamous dodgy dossier that helped take us into the disastrous Iraq War, should not be trying to give credence to these entirely false and ridiculous smears."
The Standard has contacted the Conservatives for further comment.