Guardian journalist George Monbiot has agreed a"remarkable" settlement with Lord McAlpine over a libellous tweet sent last November.
Monbiot said in a blog today that McAlpine had offered him the chance to carry out £25,000 worth of charitable work over the next three years.
He described the agreement, made with McAlpine’s representative Andrew Reid of RMPI LLP, as “unprecedented”, “remarkable and eminently decent”.
He said he had accepted the proposal “without reservation” and that it reflects well on McAlpine.
The columnist was among a number of high-profile Twitter users, including Sally Bercow who McAlpine is suing for £50,000, to suggest that a Newsnight investigation into child abuse in North Wales involved the peer.
Last month McAlpine announced he was dropping defamation claims against Twitter users with fewer than 500 followers who wrongly named him as a paedophile, instead asking for a charitable donation.
The Tory peer, who has already received six-figure payouts from the BBC and ITV, said he wanted to draw the "unfortunate episode" to a close.
On his blog Monbiot said: “In November 2012, when I had over 55,000 followers on Twitter, I did a stupid and thoughtless thing. I sent tweets hinting that Lord McAlpine was the person discussed in the Newsnight investigation of child abuse in North Wales.
“As we now know, Newsnight’s story was completely wrong. In doing so, I helped to stoke an atmosphere of innuendo around an innocent man. You can read the apology I published here. I remain extremely sorry for the harm I helped to cause him.”
He added: “I have been prompted by Lord McAlpine’s admirable proposal to do the right thing – something I should have been doing all along – and I hope very much that I am able to do it well.
“Finally, please make sure you check your facts and think before you tweet.”