Gavin Williamson has resigned as a minister after messages emerged in which he berated the former Conservative chief whip for not ensuring he was invited to the Queen’s funeral.

Williamson, who was sacked as defence secretary by Theresa May for leaking confidential information, and by Boris Johnson after a disastrous two-year stint as education secretary, was brought back to government last month by Rishi Sunak as a Cabinet Office minister.

However, his position was placed in jeopardy almost immediately after it was reported, initially by Tortoise Media, that he had sent furious messages to Wendy Morton, Truss’s chief whip, after learning he would not be among those going to the monarch’s funeral.

Full details of the messages, acquired by the Sunday Times, show Williamson, who also served as chief whip, accusing Morton of showing political preference over which ministers or former ministers attended the funeral.

It was, he texted, “very poor and sends a very clear message” that members of the privy council who were not “favoured” by Truss were being deliberately excluded. This looked “very shit”, Williamson added.

“Also don’t forget I know how this works so don’t puss [sic] me about,” he wrote. Another read: “Well let’s see how many more times you fuck us all over. There is a price for everything.”

Several ministers condemned the tone of the messages but said they had been sent in “the heat of the moment”.