Tensions between the prime minister and his chancellor have played out publicly in recent weeks, with a series of dividing lines separating them. Here are six issues Boris Johnson and Rishi Sunak have disagreed on: Net zero No 10 wants one of Johnson’s leading legacies in office to be progress on environmental issues and tackling the climate crisis. But dealing with the biggest emergency of our times comes with a price tag. The chancellor is signed up to the principle of net zero but the whole government’s strategy has been held up over arguments about how it will be paid for. Sunak, who is instinctively fiscally more conservative, is now examining how to reduce the costs for lower earners. Social care funding Johnson promised when he came to office that he would solve the crisis in social care once and for all. Two years on, he still has not announced a way of doing that, with a deal stalled because of a lack of agreement about how to pay for it. The Treasury’s favoured option is a rise in national insurance contributions but Johnson’s team has ordered a reassessment of that in the face of a backlash among Tory MPs about the breaking of a manifesto commitment not to raise that tax. Levelling up Johnson has previously described himself as a “Brexity Hezza” – a reference to the former Tory deputy prime minister Michael Heseltine, who was in favour of government spending to boost regional growth. The prime minister’s much-vaunted levelling up strategy is designed to achieve a rebalancing of the economy to help areas outside the capital achieve stronger growth and productivity. However, once again this comes at a cost. The Treasury has delivered “levelling up cash” but this has been criticised in some quarters for lacking ambition. Austerity At the heart of the differences between Johnson and Sunak is an ideological split. Johnson has pledged to end austerity and would like some big spending to deliver his priorities – even after the economic blow dealt by the coronavirus pandemic. The chancellor is much more fiscally hawkish, with an awareness that the purse strings must be tightened or tax raised if he wants to keep day-to-day spending under control. Personal popularity Johnson loves to be liked, and for much of his first two years in office has enjoyed positive ratings unusual in a leader of a governing party more than 10 years into power. However, his personal ratings have recently sunk to their lowest level since he became prime minister. In contrast, Sunak – responsible for keeping people in work through the furlough scheme – has seen his popularity soar. Last week the chancellor topped a ConservativeHome poll of who members would like to see as the next leader, with almost a third of the vote. Covid restrictions On the substance of the pandemic response, there is little between Sunak and Johnson. Both were keen to see a relaxation of UK quarantine rules amid fears the economy would otherwise lag behind other countries. Likewise, both were naturally sceptical of lockdowns. However, tensions have arisen over Sunak’s positioning as the most keen to open up the economy after the disruption of the last 18 months. The leaking of a letter from Sunak to Johnson pushing for an easing of travel restrictions caused the simmering problems to break into the open last weekend. Some around the chancellor pointed the finger at Department for Transport officials who were copied into the letter, although this was denied. Regardless, the damage in relations had already been done, as the Sunday Times later reported that an apoplectic Johnson threatened to demote Sunak to health secretary.