Central planning of any stripe leads to authoritarianism and eventually, totalitarianism. From Rob Sutton at thecritic.co.uk:
Hayek suggested a society which sacrificed liberty for security would gradually submit itself to authoritarian control
Friedrich Hayek’s The Road to Serfdom maintains a near unrivalled influence on the political imagination of conservative and classical liberal thinkers. Published in 1943, at the height of the Keynesian consensus, it elaborated a worldview considered intolerable within academic economics.
The central thesis of The Road to Serfdom is that descent into tyranny is the ultimate and inevitable trajectory of a society in which the sovereignty of the individual is subverted in the accumulation of economic power by the state. Central planning leads invariably to authoritarianism. Hayek is not timid in making these claims.
Studying the seemingly disparate political systems which dominated Europe in the run-up to the Second World War (communism, fascism, socialism), Hayek concluded that they each had a common endpoint – the development of a totalitarian state. Despite their contrasting social and economic goals, each necessitated the central consolidation of power and the explicit planning of an economy to achieve those goals.
As such, their distinct political flavours were largely irrelevant to their ultimate destination. Position along the political axis was less important than most commentators predicted. The binary Hayek was interested in, rather than left wing versus right wing, was whether the state uses its authority to promote individual freedom or to restrict it.