  We introduce the computer code Recola for the recursive generation of
tree-level and one-loop amplitudes in the Standard Model. Tree-level amplitudes
are constructed using off-shell currents instead of Feynman diagrams as basic
building blocks. One-loop amplitudes are represented as linear combinations of
tensor integrals whose coefficients are calculated similarly to the tree-level
amplitudes by recursive construction of loop off-shell currents. We introduce a
novel algorithm for the treatment of colour, assigning a colour structure to
each off-shell current which enables us to recursively construct the colour
structure of the amplitude efficiently. Recola is interfaced with a
tensor-integral library and provides complete one-loop Standard Model
amplitudes including rational terms and counterterms. As a first application we
consider Z+2jets production at the LHC and calculate with Recola the
next-to-leading-order electroweak corrections to the dominant partonic
channels.
