  The process of reconstruction of attosecond beating by interference of
two-photon transitions (RABBITT) can become resonant with a discrete atomic
level either in the intermediate or the final continuous states. Experimental
observations of the former [Phys. Rev. Lett. 104, 103003 (2010)] or latter
[Nat. Commun. 7, 10566 (2016)] cases revealed modification of only those parts
of the photoelectron spectrum that overlapped directly with the resonance. In
the lithium atom and other members of the alkali metal family, the valence
shell $ns\to np$ transition to the intermediate RABBITT state affects the whole
photoelectron spectrum in the final state. The strong additional resonant
channel modifies entirely the ionization dynamics and opens direct access to
the resonant phase of the two-photon transitions which is common for various
single and multiple electron ionization processes. Elucidation of this phase
has wider implications for strongly resonant laser-matter interaction.
