Bibliogr. s. 100-110

The subject of the paper is the analysis of current development of regulations regarding real security rights on immovables in terms of accessoriness and non-accessoriness of securities, in the context of prospects for the creation of a single mortgage market in Europe. The considerations are focused on assessing the impact accessoriness has, on one hand, on the economic efficiency of securities, and on the other hand - on the protection of the mortgagor. Among different types of securities belonging to the above category which are used in European countries, mortgage regulated under the Polish Land and Mortgage Registers and Mortgage Act, thoroughly amended in 2009, has been characterized in detail - as an example of a security based on loosened accessoriness. A point of reference within the comparative analysis of accessory and non-accessory instruments to secure loans is the proposed model of a common flexible security on real estate for the European Union Member States, i.e. the Eurohypothec. It is expected that thanks to its non-accessory character, the use of the Eurohypothec could contribute to encouraging cross-border mortgage lending and thus to the integration of the Member States' markets. However, the idea of a pan-European non-accessory real security on immovables also raises doubts, mainly because of the risk for the borrowers, resulting from breaking the link between the security and the secured claim. Examining the proposal of the Eurohypothec against the background of the dominant European tendencies in the field of real security rights on immovables provides a basis for drawingconclusions concerning actual possibilities to harmonize mortgage markets.