Andy Burnham and Wes Streeting have decided that the best way to steal the Green Party's thunder is to hint they might tax the wealthy, which is roughly as bold as a chef suggesting we use salt.

With SpaceX's stock market launch sending Elon Musk's fortune into low Earth orbit, it's dawned on most people that the super-rich are hoovering up the rewards while the rest of us fight over crumbs. Enter Gabriel Zucman, a professor who commutes between Berkeley and the Paris School of Economics, armed with charts and a book titled We Need to Tax Billionaires, published last month.

Zucman's research reveals that in 1989, the top 0.001% of UK families - about 200 of them - owned 5% of the nation's annual GDP. By 2025, that same group had gobbled up 22% of GDP, which was just over £3tn. Meanwhile, billionaires pay an effective tax rate of 25% at most, while the rest of us fork over 40% to 50%. But hey, no hard feelings.

Zucman's proposal is refreshingly simple: a 2% tax on assets over $100m, no exemptions, no loopholes. It's backed by half a dozen Nobel prize-winning economists, which is basically a full academic choir singing in harmony.

To prevent the super-rich from fleeing to Monaco or Dubai, the UK could pass a law treating long-term residents as tax residents for five to ten years after they leave. Because nothing says "I'm escaping taxes" like having the taxman follow you to the beach.

Burnham and Streeting are understandably nervous. The Daily Telegraph recently shrieked "Britain needs more wealth creation, not a tax war on billionaires," while the Financial Times fretted about "wealth tax fears." But Zucman argues that entrepreneurs who amass over £100m have been extremely lucky, benefiting from state-funded infrastructure, local amenities, and worker skills. Megabusiness owners are not islands, and if they lack civic pride, they should acquire some - perhaps from the same store where they bought their yachts.

Maybe Burnham, currently the favorite to be prime minister in the autumn if he can win this month's Makerfield byelection, can explain to the nation that taxing the super-rich isn't self-harm; it's a way to start fixing 40 years of ridiculous inequality that has undermined the fabric of what was once a contented nation.