The power briefly went out in the House of Lords as peers sat on Monday evening.
Lights in the Lords chamber flickered before going out, while a brief but loud humming sound could be heard as they faltered.
Television screens also turned off as justice minister Lord Bellamy was speaking at the despatch box.
In the House of Commons, microphones briefly cut out and lights also flickered in other parts of the estate.
Emergency lighting continued to illuminate the House of Lords during the brief power outage.
Lord Bellamy remarked on the electricity failure, telling the chamber: “Ah, I must have said something very controversial.
“I’ve still got a light so yes, thank you.”
The minister continued his speech, reading his notes by the light of a table lamp as he responded to a short debate on support for parents considering separation.
The Lords suspended its sitting shortly after Lord Bellamy concluded his speech, to await the House of Commons latest message on the Safety of Rwanda (Asylum and Immigration) Bill.
It came amid the late-night back-and-forth between the Commons and Lords over amendments to the Bill.
