However, he has now announced via a blog post that he has been suspended from the party.
Greg, pictured, left the Independent last November after it was taken over by Johnston Press in July 2015.
He wrote: “I confirm that I am the latest of many victims of the witchhunt against socialist supporters of Jeremy Corbyn within Brighton, Hove and District Labour Party (the City Party).
“After more than 10 years as a member of Labour in in our city, I have been suspended — for the second time in just over two years.
“Apparently, I have now been accused of ‘a pattern of behaviour, including intimidation of individuals, which is capable of bringing the Labour Party into disrepute’.
“Previously, I was suspended — on a similar fabricated charge — for 11 months, before it was decided that allegations against me, made by the party’s then regional director, did not even merit investigation.”
He added: “I am confident I will be found innocent again. Eventually. But only after I have been prevented from standing as a candidate in forthcoming elections.”
He served as education correspondent at Today for two years before taking up the same role at the Sunday Times, where he later became news editor and assistant editor.
He also founded football website Soccernet with his then 12-year-old son Tom in 1995, which was later sold to ESPN for £25m.