  In this article we perform a combined analysis of low energy precision
constraints and LHC searches for leptoquarks which couple to first generation
fermions. Considering all ten leptoquark representations, five scalar and five
vector ones, we study at the precision frontier the constraints from
$K\to\pi\nu\nu$, $K\to\pi e^+e^-$, $K^0-\bar K^0$ and $D^0-\bar D^0$ mixing, as
well as from experiments searching for parity violation (APV and QWEAK). We
include LHC searches for $s$-channel single resonant production, pair
production and Drell-Yan-like signatures of leptoquarks. Interestingly, we find
that the recent non-resonant di-lepton analysis of ATLAS provides stronger
bounds than the resonant searches recasted so far to constrain $t$-channel
production of leptoquarks. Taking into account all these bounds, we observe
that none of the leptoquark representations can address the so-called "Cabibbo
angle anomaly" via a direct contribution to super-allowed beta decays.
