Liz Truss has stuck by her call for lower taxes as she gave her final speech before leaving Number 10 – saying the UK “simply cannot afford to be a low growth country”.

Speaking outside Downing Street, Ms Truss, who has become the country’s shortest serving prime minister after just seven weeks, said “brighter days lie ahead” as she wished Rishi Sunak “every success” as he takes the reins.

But she appeared to double down on her political philosophy, saying: “I am more convinced than ever that we need to be bold and confront the challenges that we face.

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“As the Roman philosopher Seneca wrote, it’s not because things are difficult that we do not dare is because we do not dare that they are difficult.”

Ms Truss is now heading to Buckingham Palace to officially offer her resignation to the King.

She will be followed by the new leader of the Conservative Party, Mr Sunak, who will be asked by the King to form a new government.

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Ms Truss won the keys to Number 10 at the start of September after a summer-long leadership contest to replace Boris Johnson.

She beat Mr Sunak with 57% of the votes from party members and promised them she would “deliver, deliver, deliver”.

The start of her premiership was dominated by the death of the Queen, with her attending tribute events across the country to support the new King and giving a reading at the monarch’s funeral.

But her time in office was defined by her tax slashing mini-budget that sent markets into turmoil and the pound dropping at record rates.

Ms Truss tried to regain her authority by firing her Chancellor Kwasi Kwarteng and replacing him with Jeremy Hunt, who within days had reversed nearly all her policies.

But after the resignation of her home secretary and chaos in parliament over a vote on fracking, she said she accepted she could no longer stay in post.

Mr Sunak was chosen to replace her by Tory MPs four days later, and will shortly become the country’s new prime minister.