We present the results from the phase A study of ELT-HIRES, an optical-infrared, high-resolution spectrograph for ELT, which has just been completed by a consortium of 30 institutes from 12 countries forming a team of about 200 scientists and engineers. The top science cases of ELT-HIRES will be the detection of life signatures from exoplanet atmospheres, tests on the stability of Nature's fundamental couplings, the direct detection of the cosmic acceleration. However, the science requirements of these science cases enable many other groundbreaking science cases. The baseline design, which allows fulfilling the top science cases, consists in a modular fibre-fed cross-dispersed echelle spectrograph with two ultra-stable spectral arms providing a simultaneous spectral range of 0.4-1.8 μm at a spectral resolution of 100,000. The fibre-feeding allows ELT-HIRES to have several, interchangeable observing modes including an SCAO module and a small diffraction-limited IFU.