Rishi Sunak delivered the stark message after being confirmed as the next PM when his sole remaining rival Penny Mordaunt failed to make the threshold of 100 nominations needed to trigger a run-off. Speaking to a camera at Conservative HQ, Mr Sunak said the UK is a 'great country' and vowed to work 'day in and day out', but pointed to serious economic problems. Earlier, the new premier received a rapturous reception when he made a 10-minute private speech to MPs at Parliament, telling his troops that Mr Johnson, Ms Mordaunt and Ms Truss were 'all good Conservative colleagues and friends', adding: 'We're united behind the policy and now cannot afford the indulgence of division over personality. According to one MP present he said: 'We have one chance. It is unite or die.' It marks a spectacular political revival for Mr Sunak, just seven weeks after he was soundly defeated by Liz Truss in the struggle to succeed Mr Johnson. But after her extraordinary 44-day implosion, he now faces one of the toughest in-trays for any PM with the public finances in chaos and the worst of the cost-of-living to come. Mr Sunak is expected to be formally installed as premier by King Charles tomorrow.