Britain's Home Secretary Amber Rudd arrives in Downing Street for an emergency Cabinet meeting in London,  May 23, 2017.
FILE - Amber Rudd arrives in Downing Street for an emergency Cabinet meeting in London, May 23, 2017.

A senior minister of Britain's ruling Conservative party has resigned because she does not think the prime minister is serious about creating a Brexit divorce deal. 

Work and Pensions Secretary Amber Rudd said late Saturday that Boris Johnson is not working to secure a Brexit withdrawal agreement. 

"There is no evidence of a deal," Rudd said.  "There are no formal negotiations taking place." 

Rudd said in her resignation letter: "I joined your cabinet in good faith: Accepting that 'no deal' had to be on the table, because it was the means by which we would have the best chance of achieving a new deal to leave on 31 October." 

Rudd added: "The government is expending a lot of energy to prepare for 'no deal' but I have not seen the same level of intensity go into our talks with the European Union." 

Home Secretary Sajid Javid said Sunday the government is "straining every sinew to get a deal."