to fund local government, instituted in 1989 by the government of Margaret Thatcher. It replaced the rates that were based on the notional rental value of a house. The abolition of rates was in the Conservative Party manifesto for the 1979 general election; the replacement was proposed in the Green Paper of 1986, Paying for Local Government based on ideas developed by Dr. Madsen Pirie and Douglas Mason of the Adam Smith Institute. It was a fixed tax per adult resident, but there was a reduction for those with lower household income. Each person was to pay for the services provided in their community. This proposal was contained in the Conservative Party manifesto for the 1987 general election. The new tax replaced the rates in Scotland from the start of the 1989/90 financial year and in England and Wales from the start of the 1990/91 financial year. The system was very unpopular since many thought it shifted the tax burden from the rich to the poor, as it was based on the number of occupants living in a house, rather than on the estimated market value of the house. Many tax rates set by local councils proved to be much higher than earlier predictions since the councils realised that not they but the central government would be blamed for the tax, which led to resentment, even among some who had supported the introduction of it. The tax in different boroughs differed because local taxes paid by businesses varied and grants by central government to local authorities sometimes varied capriciously. Mass protests were called by the All Britain Anti-Poll Tax Federation with which the vast majority of local Anti-Poll Tax Unions (APTUs) were affiliated. In Scotland, the APTUs called for mass nonpayment, which rapidly gathered widespread support and spread as far as England and Wales even though no-payment meant that people could be prosecuted. In some areas, 30% of former ratepayers defaulted. While owner-occupiers were easy to tax, nonpayers who regularly changed accommodation were almost impossible to trace. The cost of collecting the tax rose steeply, and its returns fell. Unrest grew and resulted in a number of poll tax riots. The most serious was in a protest at Trafalgar Square, London, on 31 March 1990, of more than 200,000 protesters. Terry Fields, Labour MP for Liverpool Broadgreen, was jailed for 60 days for his refusal to pay the poll tax.