A Labour MP has described the "dark spectre" the Holocaust cast over his family, during a debate focused on Holocaust Memorial Day.

Alex Sobel's voice cracked as he told MPs of seeing the numbers tattooed on his great aunt's arm and asking his father:"Why?"

"She didn't have her own children or grandchildren, I had no aunts and uncles or cousins to play with, because the Nazis experimented on her and she couldn't have children," he said.

"This hollow shell casts a dark spectre over my family - all the relatives I never met, that never survived, the children they never had."