Electra, 39, was given a frosty reception at the Hammersmith Apollo tryouts and individual audience members shouted 'bring back Amanda Holden' during the former Baywatch star's comments to the acts.
David Walliams made Tuesday's auditions more awkward for Electra when he mocked her comments about a young male singer's voice changing as he grows up.
"It will get deeper obviously," Walliams said sarcastically.
Simon Cowell appointed Electra as a part-time replacement for Holden, who is currently on leave after giving birth to her daughter Hollie.
Holden will return to the show when the auditions move to Edinburgh later this week.
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