A solution exists: an advance in our understanding of justice that goes beyond Liberalism--without betraying any of its achievements. We must understand that the ethic of justice is mutual respect.

A society governed by mutual respect would have the maximum liberty that coexisting people can share simultaneously. Properly understood, liberty is the product of justice, not its source, or foundation, or predicate, etc. As individuals, the minimum mutual respect requires of us is to refrain from killing, harming, coercing, stealing, and manipulating (which includes lying, cheating, etc.) in our relations with one another. Surely we can all manage that; to the extent that we do, we are being just enough.

That society would (still, in the UK) have a democratic political process. I.e., there would be freedom of political speech and a 'democratic distribution' of political rights: i.e., the only valid restrictions on any political right would be universally applicable and universally applied (meaning as a practical matter that age is the only valid restriction).

That society would have (in the UK) the same economic system as now exists, but with (for--adult--citizens) no unemployment and poverty. As well, the hoary practice of using taxes and public debt to fund government would be ended (as long as government did not exceed anywhere its allotted funding, which would be forevermore the current per capita rate of total government spending). At the same time, sustainability would be systemically increased. All of that would be achieved without redistributing anything, without imposing limit on income/wealth, and without requiring people to act any particular way. It could be accomplished with a single Act of Parliament.