The LHeC is the highest energy hadron-electron collider under design. It achieves 1 (3.5) TeV energy in the centre of mass by combining a new electron beam of about 60 GeV energy with the proton beam of the LHC (or in the future the FCC_hh). The exploration of rare phenomena, such as the Higgs boson and of the substructure of matter at smallest dimensions, requires that the LHeC achieved luminosities of O(1034)cm-2s-1, which is a factor of ~1000 higher than HERA. This can only be achieved with an energy recovery linear accelerator, with currents of about 10mA. Currently, an international collaboration is designing an ERL Test Facility for CERN (LTFC), as sketched above. Besides possibly preparing for the LHeC, it has a number of further important applications, still under consideration, such as tests of SC RF (at 802 MHz) under operational conditions, magnet and detector tests and possibly ep and photon physics too. The LTFC is designed in a modular way for eventually 3 passes and to deliver about 1 GeV of electron beam energy in its complete configuration.