Suella Braverman, who was sacked as UK's home secretary on Monday, accused Prime Minister Rishi Sunak of "betrayal" of promise to stop the "small boats," referring to irregular migrants.
In her letter to the premier on Tuesday, the former home secretary broke silence a day after she was asked to leave the post, saying: "Someone needs to be honest."
"Despite you having been rejected by a majority of party members during the summer leadership contest and thus having no personal mandate to be prime minister, I agreed to support you because of the firm assurances you gave me on key policy priorities," said the letter, defined by many as "scathing."
Touching on priorities, including tackling irregular migration and delivering the Northern Ireland Protocol, she said Sunak failed on these policies.
"You have manifestly and repeatedly failed to deliver on every single one of these key policies."
She also accused him of a "betrayal of our agreement" and a "betrayal of your promise to the nation that you would do 'whatever it takes' to stop the boats."
Braverman went on to say that the prime minister also failed "to rise to the challenge posed by the increasingly vicious antisemitism and extremism displayed on our streets."
"Someone needs to be honest: your plan is not working, we have endured record election defeats, your resets have failed and we are running out of time," she opined, adding she will continue to support the government "in pursuit of policies which align with an authentic conservative agenda."
As part of Monday's reshuffle, Braverman was sacked as home secretary and replaced by James Cleverly, the former foreign secretary.
The controversial Rwanda plan that seeks to deport asylum seekers to Rwanda while their claims are assessed, and her remarks calling pro-Palestine rallies anti-Semitic "hate marchers" sparked widespread criticism.
She was also under fire from other political parties due to her stance against protesters who have been taking to British streets since the start of Israel's ongoing bombardment of the Gaza Strip.
For her, the writing was on the wall since she penned a controversial article last week in a daily, attacking the Metropolitan Police for their tolerance toward the peace marchers.
"The hate marchers need to understand that decent British people have had enough of these displays of thuggish intimidation and extremism," she wrote on X.
