A leading free market thinktank claims Ed Miliband's pledge to cap rent rises in the private sector "defy economic logic" and will end up harming the poor.
Mark Littlewood, director general of the Institute of Economic Affairs, said the proposal to make tenancies three years long might "lead to landlords being uncooperative in the hope that tenants leave early".
He claimed the "key factor" in high rents was a shortage of housing and called on politicians to reform "draconian planning laws" to boost supply.
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