This paper analyzes a relationship between the size of governmentexpenditure and political structure in the parliament. It considers a politicalrent-seeking economy in which the size of government expenditure isdetermined by the rent-seeking politicians and the lobbying groups of voters.The pressure groups seek economic rents to influence the choice of thepoliticians. According to the results of the model, the larger the politicalconcentration in the parliament or the more competitive the lobby-market forpolitical rents, the larger the equilibrium level of government expenditure.The empirical results confirms that the political concentration in the localparliament affects the size of local government expenditure.