The historical segregation between international trade and investment law is fading away largely due to the commencement of vertical FDI.Despite its efforts, the WTO has remained unsuccessful to serve as a common platform for both.Regional trade agreements (RTAs) have stepped into this vacuum as an alternate and their economic viability shows that this trend will continue to grow.This convergence of international trade and investment laws has boosted the volume of both cross border　　trade and investment flows, however it enhanced the possibilities of already existing legal challenges e.g.parallel, intra-regime and inter-regime enforcement of remedies involving trade and investment laws.Despite the fact, FDI is an important source for economic and social development its legal regime generally and ISDS mechanism particularly facing severe criticism for being skewed in the favor of investors and creating chilling impact on host States regulatory autonomy.Efforts are being made both at national and international levels to address this issue; however these are largely premised on the context of segregated treatment of investment law.RTAs with varying levels　　of commitment towards social and environmental issues along with augmented possibilities to impede regulatory autonomy portend new challenges.Consequently, this phenomenon may prospectively undermine the accomplishment of globally cherished goal of sustainable development.Therefore an integrated approach encompassing both substantive and enforcement aspects of investment law moreover compatible with international law regime is required.