The diminution of private-rented housing, the traditional source of shelter for those denied access to the owner-occupied sector, eventually led to direct government intervention (Balchin 1985). The growth of municipal housing however cannot be attributed to a single cause. Other important motivating factors were the failure of nineteenth-century philanthropic housing associations to demonstrate that it was possible to provide decent dwellings at a rent affordable by the low-paid, increased working-class militancy over housing conditions vividly displayed in the Glasgow rent strikes of 1915, the shortage of housing in the post-First World War era, and a gradual shift away from the dominant Victorian ideology of self-help and the pervading belief in the efficiency of the market mechanism. Taken in combination those factors led the state to pass the 1919 Housing Act (Addision Act) which offered subsidies to local authorities to make up losses incurred in providing homes over and above those borne by a one-penny rate (Merrett 1979). The Wheatley Act 1924 gave a major boost to council-house building with over 500,000 houses stemming from this legislation but for the great majority of working class accommodation was still to be found in the private-rented sector. The poorest of the working class still lived in overcrowded slum conditions.