Brexit Secretary David Davis was on the receiving end of a blast from Dominic Cummings | Stephanie Lecocq/EPA Leave campaign boss says David Davis is ‘thick as mince’ Dominic Cummings hits out at Brexit secretary and the head of the UK civil service.

Dominic Cummings, the former campaign director of the Vote Leave campaign, fired a broadside at Brexit Secretary David Davis on Monday, the day that the first full round of EU exit talks got underway.

Cummings said in a tweet that "DD [Davis] is manufactured exactly to specification as the perfect stooge for [Cabinet Secretary Jeremy] Heywood: thick as mince, lazy as a toad, & vain as Narcissus." Heywood is the head of the U.K. civil service and has been chief fixer to four successive British prime ministers.

DD is manufactured exactly to specification as the perfect stooge for Heywood: thick as mince, lazy as a toad, & vain as Narcissus — odysseanproject (@odysseanproject) July 17, 2017

Heywood and Cummings have a troubled past. The Vote Leave chief is a close ally of leading Brexiteers Michael Gove and Boris Johnson, and it was widely believed that they planned to dump Heywood if one of them became prime minister.

Cummings blamed the decision to create two new departments in the aftermath of the Brexit referendum — one for exiting the EU, the other for international trade — on Heywood, calling the reorganization “stupid.”

Last week, Cummings said government officials in favor of leaving the nuclear body Euratom were “morons” and criticized the “truck loads of crap ideas” from Theresa May’s first months in office.