British Prime Minister Boris Johnson has asked officials to “establish the facts” by launching an inquiry into allegations of bullying against interior minister Priti Patel, senior minister Michael Gove said on Monday.

On Saturday, Philip Rutnam, Britain’s top official in the interior ministry or Home Office, resigned, saying he had become the “target of vicious and orchestrated campaign against him” which, he alleged, Patel was involved in.

“Allegations have been made that the home secretary has breached the ministerial code. The home secretary absolutely rejects these allegations,” Gove told parliament.

“This government always takes any complaints relating to the ministerial code seriously and in line with the process set out in the ministerial code, the prime minister has asked the cabinet office to establish the facts.” Patel has been driving through changes in UK’s immigration policy.