Investment in past fusion experiments has been motivated largely by the study of tokamak physics, and has been vital to provide a sound physics basis for design of a power reactor. However, meeting the challenge of realising fusion energy production will require considerable and increasing investment in facilities for testing and development of fusion technology. Particularly important will be testing of components destined for the harsh in-vessel environment of the reactor, which present the major unresolved technological challenges. To help address this need the UK Government is investing in major new fusion technology facilities (FTF) for the UK, which will offer integrated laboratories covering the complete development life cycle from materials to manufacturing processes and load testing of components. A major part of the FTF shall be a test device, initially known as the Module Test Facility (MTF), offering testing under fusion relevant loads for metre-scale in-vessel component mock-ups. Among the major challenges addressed are high heat flux, extreme thermal cycling, electromagnetic loads, and proving complex and high-risk manufacturing. The ability to test technology in magnetic fields will be unparalleled, and could prove vital for breeding blanket designs featuring a ferromagnetic structural material (e.g. Eurofer97) or a liquid metal breeder with consequent MHD phenomena. Further, in order to provide semi-integrated testing including possible synergistic effects, the MTF will enable tests of resilience against the above multiple loads in combination – a unique offering. This paper presents the plans and planned capability of the MTF and describes the status of the concept design. The starting high level requirements are testing on large components of at least 1 m size, cooled using water at 150ºC, 50 bar or up to 325ºC, 155 bar. A magnet system shall create a strong static magnetic field over the component with peak field of at least 4 Tesla, and combine this with a magnetic pulse simulating a plasma disruption, with dB/dt of ~20 T/s. A surface heating system shall be capable of 0.5-1 MW/m² surface power density over 1 m², and 20 MW/m² in localised areas. Volumetric heating power is also planned in order to simulate nuclear heating of blanket mock-ups. A key theme in the MTF will be highly instrumented testing, enabling thorough diagnosis of performance and failure modes and delivery of abundant engineering data. A major objective is to perform experiments on mock-ups in order to validate computational modelling and develop digital twins for predictive modelling and design in-silico. Further, it is planned to use non-destructive testing and advanced sensors and instrumentation to develop lifetime monitoring techniques for eventual nuclear devices, in which diagnostic data will be sparse. The design, manufacturing and installation of the MTF is being contracted into industry. Initial design contracts have been placed and a concept design is presented in this paper. Magnet system design and manufacturing feasibility studies have been completed by superconducting magnet suppliers. The contract for overall design integration and the first manufacturing contracts are planned to be let during 2019.