The Blues slumped to a seventh successive defeat last night.
A 3-2 victory for Leyton Orient at Fratton Park ensures Pompey are now on their worst losing streak for 37 years.
The side were booed off by sections of the Fratton faithful at half-time as they headed in 1-0 down after an abject first 45 minutes.
At the interval, Whittingham revealed Andy Awford let rip at the Blues players.
The hosts were also sent out around five minutes early for the second half.
Pompey improved considerably after the break, yet still ran out losers.
But the caretaker boss was fuming at that first-half showing. And Whittingham admitted the fans were correct in venting their feelings.
He said: ‘I’m glad they (the fans) let the players know by booing because you have to.
‘That was probably as bad as I have seen them this season in that first half.
‘I was only involved in home games before but that first-half performance wasn’t acceptable.
‘You can understand if confidence isn’t high but there is no excuse for not working hard.
‘There is no excuse whatsoever for not running around.
‘There wasn’t passion there, it was too easy for the opposition. We weren’t getting close enough to them.
‘All that is hard work.
‘Awfs told them in no uncertain terms what people expect here and who they are.
‘They are professional football players and the very least they should be doing is running around.
‘You don’t want to go back to when you were playing but the very least you gave was 100 per cent.
‘You should expect any supporter, member of staff or any player to do the same.
‘Although, it was certainly a better performance in the second half.’
Not since Ian St John’s team in the 1975-76 campaign has a Pompey team endured such a lengthy losing run.
That season culminated in relegation to the old division three.
Pompey now find themselves in the relegation zone following their latest loss.
They travel to improving Coventry on Saturday.
Whittingham is hopeful for at least two new faces in place for that fixture, with the emergency loan window closing tomorrow at 5pm.
One of those is expected to be keeper Alex Cisak.
In the meantime, the caretaker boss explained the reasoning for his players arriving on the pitch early for last night’s second half.
He added: ‘It was partly because of the way they had played but we also felt the past couple of games we hadn’t started the second half very well.
‘It was a decision made after the previous game (Doncaster).’