Party Election Broadcasts (PEBs) which made the Broadcast top 100 overnights for last week:
#72 - Liberal Democrats (Fri, 18:25, ITV): 3.24m (18.5%) inc +1
#77 - Conservatives (Tue, 18:25, ITV) : 3.15m (18.4%) inc +1
#82 - UK Independence Party (Wed, 18:25, ITV): 3.10m (18.5%) inc +1
#91 - Labour (Thu, 18:25, ITV): 2.87m (18.4%) inc +1
Source: Broadcast magazine
Remarkably consistent shares in that slot.
I'm sure some (if not all) of the BBC One showings would also have charted, were it not for a quirk of tape-checking. The BBC One transmissions typically ran from 18:54 - 18:57, and so after tape-checking they must have disappeared from the overnight data, being deemed to run from 18:55 to 18:55!
There was a UKIP PEB on BBC One on Wednesday 23rd which ran from 18:52 to 18:57 which in theory should have charted if it got more than 2.56m, but it's not in the chart.