Nick Timothy, the Birmingham-born former adviser to Theresa May, has closed his Twitter account as the row over the Windrush scandal continues.
It comes after his attempts to defend Mrs May backfired.
Mr Timothy, who now writes a column for the Daily Telegraph, had claimed that the Prime Minister was not to blame for vans with billboards urging migrants who had overstayed their visas to "go home".
The vans appeared while she was Home Secretary, and were part of a Government policy designed to create a "hostile environment" for illegal immigrants.
The "hostile environment" policy is seen as contributing to the way British people from Commonwealth countries, sometimes referred to as the Windrush generation, have been treated. Some were denied NHS care, lost their jobs or threatened with deportation.
Mr Timothy said on Twitter: "TM was opposed to them and they were approved while she was on holiday in 2013."
But a former senior home office official has told Business Insider that the then Home Secretary actually spoke to aides about the vans while she was away, and insisted that the language on them be "toughened up."
The report was seized on by Labour leader Jeremy Corbyn, who said: "The revelation Theresa May wanted to 'toughen' the message on those hateful Go Home vans points to a nastiness at the heart of Government.
"This is not what our country is about. The Prime Minister should apologise for authorising this ugly campaign."
Mr Timothy now appears to be deleted his Twitter account, which was previously at @nickjtimothy.
He was Mrs May's special advisor at the Home Office, and worked for her in Downing Street as joint chief of staff from the time she became Prime Minister until his resignation in 2017, following the general election.
He was born in Birmingham and educated at King Edward VI Aston. Some newspapers have referred to him as the Brummie Rasputin, a reference to the monk who advised the Russian Tsar and who had a long beard, which Mr Timothy had in the past.