The perturbative instability of NLO collinear factorisation (CF) computations of pT-integrated cross sections of heavy quarkonium production at high hadronic or photon-hadron collision energy is discussed. We resolve this problem via the matching of NLO CF computation with the resummation of higher-order corrections ∝αsnlnn−1(sˆ/M2) at high partonic center of mass energies sˆ≫M2. The resummation is performed in the Doubly-Logarithmic Approximation (DLA) of High-Energy Factorisation (HEF) formalism. We also report the results of the first computation of one-loop corrections to impact-factors involving heavy quark-antiquark pair in the intermediate states considered in the Non-Relativistic QCD (NRQCD) factorisation formalism for quarkonium production: QQ¯[S0[8]1] and QQ¯[S0[1]1]. These results are necessary for the extension of our resummation formalism beyond DLA.