Lord Rennard has had his suspension from the Liberal Democrats lifted after disciplinary action linked to allegations of pestering women was dropped.
The party authorities decided not to proceed over claims the former chief executive had brought the Lib Dems into disrepute by failing to apologise.
Last year's independent investigation by Alistair Webster QC concluded that the evidence against him was "broadly credible" and urged the peer to apologise. However, Lord Rennard refused to say sorry immediately and was suspended.
In a statement, Lord Rennard said he was "pleased" with the result, adding: "The worst that might be said of me in that report was that I may have inadvertently encroached on the personal space of some of the complainants, and I apologised for this to all four of them."
But Labour's spokeswoman for women and equalities, Gloria De Piero, claimed Lib Dem leader Nick Clegg had "failed to show leadership".