The woman appointed by Boris Johnson to lead his daily press operations was left in tears on Saturday after she claimed to have been the subject of negative briefings by a former No 10 official who resigned last week and made a dramatic exit from Downing Street. In an extraordinary escalation of feuding involving new and departing aides to Johnson, friends of Allegra Stratton, the new press secretary to the prime minister, said she had been “in tears all morning” as a result of what she believed were critical briefings by Johnson’s former director of communications, Lee Cain. Stratton, who will be the public face of the government, believes Cain told numerous journalists over the previous 24 hours that she was not the first choice for the job and had not been top of the list of a panel chosen to make the high-profile appointment. Cain is a close ally of Dominic Cummings, Johnson’s former closest adviser, who also resigned last week and was asked to leave on Friday. The news came as allies of Cummings and Cain said their enemies in government were “determined to set fire to [Johnson’s] premiership” with a “tsunami of toxic briefings” that would ultimately undermine the government. Another government figure said: “It’s a bloodbath, isn’t it?” Stratton, a former Guardian and television journalist who was working for the chancellor, Rishi Sunak, before being appointed by Johnson, was said to be deeply distressed, as her reason for taking the job was to help restore civility and some order to Downing Street. A close friend of Stratton said: “Allegra is very upset. It was the prime minister who asked her to do the job multiple times. She did not apply to do it, but Johnson appealed to her sense of public duty. “She wants to broaden the appeal of this government. She likes and respects Johnson. But she thinks that this government has to date managed to make enemies and crossed the road to pick fights, that this government has narrowed its appeal and should be doing better.” Stratton later told the Observer: “Yes, I am upset because I was only ever trying to do the right thing by the country. And the country does not want to be run by people in No 10 who treat people discourteously and unpleasantly.” Her decision to break cover follows an extraordinary week in which Cummings, the closest but most controversial adviser to Johnson, and Cain, the PM’s director of communications, both resigned and were urged by Johnson to leave Downing Street without delay on Friday. The move followed rows over leaks of government announcements and premature claims – reported in some media – that Cain was to become Johnson’s new chief of staff. Another friend of Stratton said she believed Cain “was telling journalists that she was not first in line for the job … that they did not want her. There has been this tug of war between her and Lee and Dom”. Stratton is understood to have made clear throughout discussions on her appointment that she would not serve under Cain, because of what she saw as his abrupt style and treatment of junior advisers. Her decision to make a public statement before the daily briefings even begin is evidence of how serious the internal warfare inside No 10 has become. Allies of Cain said on Saturday night that he had “never briefed against anybody” and added that the former director of communications “had always been clear that Allegra had been the first choice of the prime minister”. However, Cummings and Cain’s supporters pointed out that she had performed less well than other candidates in interviews and did not impress focus groups as much as others. Senior sources in No 10 made clear on Saturday night that the prime minister is now preparing for big changes to his teams both in Downing Street and the cabinet, with a ministerial reshuffle “in January, or maybe earlier”. “We have got to strengthen the cabinet and fill posts that are vacant so there will be changes,” said one. According to one government source, Johnson was warned that Stratton’s appointment would represent “cronyism” because of her friendship with Carrie Symonds, the prime minister’s fiancee and former Tory communications director. An opponent of Stratton’s appointment said Ellie Price, the BBC journalist, was “head and shoulders” above the other candidates during an official selection process for the job. Despite the departure of Cummings and Cain, Johnson is understood to have told a group of officials in Downing Street that he wanted to get “the band back together” for the 2024 election. Cain handed in his resignation following the fallout from Stratton’s appointment. The prime minister is understood to have attempted to reverse the decision and offered him the role of chief of staff, but Cain quit after news of the job offer leaked. Insiders said there was visible upset among the prime minister’s team as the fallout continued, with aides desperately ringing around to make sure there would not be further resignations. “This is bloody even by Westminster standards,” said one Whitehall figure. “It’s almost embarrassing. The person who suffers is the prime minister, who’s a good man trying to do very difficult things. This is a huge distraction.”