As worldwide migration continues to grow, valid and reliable instruments are needed to assess the psychological processes that influence the successful management of intercultural relations in different sociopolitical contexts. In this study, we test whether the original Multicultural Ideology Scale (MCI) required a revision to remain 'fit for purpose' in the current culturally plural context of the UK (MCI-r). Specifically, six subscales are proposed to underlie the construct of a multicultural ideology: Cultural Maintenance, Equity/Inclusion, Social interaction, Essentialistic Boundaries, Extent of Differences, and Consequences of Diversity. With data from 300 UK nationals, we tested the psychometric properties of the MCI-r using various confirmatory factor analysis techniques to estimate the scale's factor structure followed by convergent and discriminant validity tests. The results indicated that a 4-factor solution (Cultural Maintenance, Equity/Inclusion, Social interaction, and Consequences of Diversity) fitted the data best. All four subscales demonstrated adequate internal consistency as well as convergent and discriminant validity. All four subscales were also negatively correlated with a right-wing political orientation, whilst especially Social Interaction and Consequences of Diversity were positively associated with intergroup contact frequency across domains (work, family and friends and/or acquaintances). Finally, UK participants with personal migratory experiences reported a stronger belief in positive consequences of multiculturalism and more support for Social Interactions between members of different ethnic groups. Overall, findings provide first insights into the applicability of the MCI-r as a reliable and valid tool for the assessment of multiculturalism within the present UK context.