COMPARATIVE ANALYSIS OF THE INVOLVEMENT OF NATIONAL PARLIAMENTS IN THE REFORM OF EU MIGRATION, ASYLUM AND EXTERNAL BORDER CONTROL POLICIES IN 2015-2020 The article tries to describe and explain the change in the involvement of national parliaments in the process of reforming the EU’s migration, asylum and bord control policies in the years 2015-2020. The research continues the threads that author have presented in the article entitled The involvement of national parliaments in 2015–2017 in actions to overcome the immigration crisis in the EU published in 2018. However, this analysis was mainly exploratory and descriptive. Therefore, by using a hypothetico-deductive method and drawing from observations about the activity of parliaments in using the treaty and non-treaty tools available to them, as well as from the conclusions about their involvement in the reform of migration, asylum and border control policies in 2015-2016, two hypotheses are tested: H1. The instrument of political dialogue was used more frequently by national parliaments during the 2020 reform than during the 2015-2016 reform; H2. Those parliaments that actively used treaty-based instruments in 2015-2016 were more likely to submit opinions on documents regarding the reform of asylum and migration policy after 2020. The results obtained show a decline in the involvement of parliaments measured by the number of political dialogue opinions sent to the EU institutions and the intensity of discussions in interparliamentary cooperation bodies. Nevertheless, the relatively large number of reasoned opinions under the subsidiarity control procedures, as well as the fact that new parliaments, which were not involved in issuing opinions on solutions regarding migration, asylum and border control policies in 2015-2016, allow us to ask new interesting research questions requiring further analysis.