Sources highlight the poor organisational practices of the construction industry in many developing countries that result in low productivity levels in labour operations. This study aimed to identify the critical factors related to the management/organisational practices that significantly influence the labour productivity in Sri Lankan building construction projects based on the perspectives of engineers. The study methodology encompassed both qualitative and quantitative approaches through a comprehensive literature review, a questionnaire survey and a series of industry consultative meetings. The study determined 31 critical factors, where salary delays, low salaries for labourers, lack of labour training facilities, poor labour management and lack of labour motivation were found in the top five rankings. Statistical tests ensured the validity and reliability of the results. Overall findings highlight the need for reinforcing the current organisational policies of construction firms related to financial processes, communication approaches, resource management and performance management practices to the new normal situations. The study outcomes may push the industry to reduce the gap between the management policies and labour operations. Though the study findings are limited to the Sri Lankan construction sector, some of them may also be tested in other developing countries in similar scenarios.