Jack Monroe, who writes for the Guardian, is to sue controversial columnist Katie Hopkins.
The Mail Online columnist accused Monroe of having sympathy for the vandalisation of a war memorial.
Monroe confirmed to the Guardian that they intend to sue Hopkins, after the latter also admitted confusing them with another writer.
Last May, after a war memorial was vandalised with the words “fuck Tory scum”, Hopkins tweeted Monroe asking them: “Scrawled on any memorials lately? Vandalised the memory of those who fought for your freedom? Grandma got any more medals?”
Monroe tweeted to Hopkins saying they would not sue if she paid £5,000 to a charity supporting migrants, and issued an apology.
The columnist also denied the accusation, saying they had family in the armed forces.
They said it would be cheaper for Hopkins to pay the money than defend herself in court.
Rather than apologising, Hopkins deleted her original tweet and admitted that she had meant to tweet writer Laurie Penny, who has also written for publications including the Guardian.
Penny had written an article offering support for protesters.
Having issued the legal complaint, it is understood that Monroe is demanding as much as £50,000 over the tweet, but has made no other comments.
Hopkins has also made no public comment on the matter.
Monroe, who blogs for various publication including the Guardian, revealed their decision to come out as nonbinary transgender on Twitter last year.