Mr Javid warned that the UK is “sleepwalking into a high-tax, low-growth economy” as he endorsed Ms Truss’s plans for radical tax cuts.
Sajid Javid has thrown his support behind Liz Truss as the next Conservative Party leader, in what will come as a huge blow to Rishi Sunak.
The former health secretary, and ex-leadership hopeful, attacked Mr Sunak’s economic policies as he revealed his choice in The Times this evening.
He suggested Mr Sunak’s refusal to cut taxes meant the UK risks “sleepwalking into a high-tax, low-growth economy” with a loss of “global influence and power”.
Whereas he said Ms Truss had a “bold agenda” that can beat Labour and “save Britain from sliding into the middle ranks”.
He wrote: “Some claim that tax cuts can only come once we have growth. I believe the exact opposite – tax cuts are a prerequisite for growth.
“Tax cuts now are essential. There are no risk-free options in government. However, in my view, not cutting taxes carries an even greater risk.”
Mr Javid launched a leadership run on a platform of swift tax cuts but quickly pulled out, struggling to win enough nominations from Tory MPs to go through to the first round of voting.
The former health secretary quit Boris Johnson’s cabinet in June, leading a wave of resignations.
In his letter to the prime minister, Mr Javid said he could “no longer, in good conscience, continue serving in this government” as he referenced the tone and values of Mr Johnson reflecting “on your colleagues, your party and ultimately the country”.
He added: “It is clear to me that this situation will not change under your leadership – and you have therefore lost my confidence too.”
Mr Javid is the latest high profile Tory MP to back Ms Truss, after she received the support of Tom Tugendhat and Defence Secretary Ben Wallace last week.