LiteBIRD is the next-generation CMB space mission designed to produce full-sky polarization maps with unprecedented sensitivity. Spain contributes to the scientific exploitation, to the data-processing centres that will support operations and analysis to the mission, and to the technological development of the payload through the Temperature Monitoring and Compensation System (TMCS). The TMCS is responsible for monitoring the instrument’s thermal environment, with particular focus on the sub-kelvin cryogenic stage that sets the operating temperature of the Transition Edge Sensor (TES) detectors. This stage operates near 100 mK, where the scientific requirements impose thermal stability at the level of a few micro-kelvin—or even fractions of a micro-kelvin—over the relevant time scales (<0.1uHz - 5Hz). Achieving such performance, while potentially compensating for temperature fluctuations induced by cosmic-ray impacts and sky-background variations on the focal plane, constitutes a major technical challenge. The ongoing prototyping activities are therefore centred on identifying the critical functions of the TMCS electronics, developing dedicated electronic designs for each of them, and validating their feasibility through targeted tests. A first complete readout chain has been implemented to characterise components, evaluate noise and stability performance, verify subsystem functionality, and determine the architectural refinements required for the next design iteration. This presentation will summarise the thermal and stability requirements of the LiteBIRD instrument, describe the architecture and expected performance of the TMCS readout electronics, and present the results obtained during the current validation campaign. Finally, the status and needs of the room-temperature and sub-kelvin test benches, as well as the key development activities planned for the coming months, will be outlined.