The Mail on Sunday’s incoming editor has sacked his newspaper’s star columnist Rachel Johnson as part of the ongoing recriminations accompanying the departure of the Daily Mail editor Paul Dacre.

Johnson was let go by the Sunday paper’s new boss, Ted Verity, just weeks after she was given a year-long contract extension by its outgoing editor Geordie Greig.

Remain-supporting Greig is preparing to replace Dacre, an arch Brexiter, as editor of the daily newspaper early next month, prompting a rapid turnover of jobs and a very public war of words as Greig tries to find a way to soften the paper’s tone on leaving the EU.

Verity by comparison is a Dacre loyalist who until recently served as deputy editor of the Daily Mail. Despite sharing the same owners and working in the same building the Daily Mail and Mail on Sunday view each other as rivals and often adopt conflicting editorial stances.

Johnson confirmed her imminent departure to the Guardian: “I’ve had six glorious years with Geordie and it’s only right that Ted Verity brings in his own people. I completely understand and respect his decision.”

The decision raises further questions about the influence Dacre will have over the news outlets in the future. He is due to move upstairs to become chairman of their parent company Associated Newspapers.

Dacre used a valedictory column for the Spectator earlier this year to insist the Daily Mail continue to back Brexit. He also singled out Johnson’s Mail on Sunday column for criticism, saying her writing “gives banality a bad name”.

Johnson, who has also been editor of The Lady magazine and a contestant on Celebrity Big Brother, has been an outspoken supporter of Britain remaining in the EU in line with the Mail on Sunday’s policy under Greig.

She joined the Liberal Democrats last year in protest at the government’s Brexit policy and even toyed with the idea of standing for parliament. She was nominated as columnist of the year in this year’s British Press Awards.

News of her departure comes soon after her brother Boris Johnson, the former foreign secretary and prominent figure in the Vote Leave campaign, returned to his weekly Daily Telegraph column, for which he was previously paid more than £250,000 a year.

Rachel Johnson defended her sibling’s decision to write a column criticising the burkha earlier this month, while noting it was a “sun-lounger piece” which “read like a column written on a Sunday morning while on holiday in Italy, with a bottle or two of Asti Spumante chilling in the fridge for lunch”.