Charity workers were left disappointed after Ann Keen cancelled two engagements due to problems with her teeth.
Health Minister Ann was supposed to be working behind the till at the Cancer Research UK shop in Chiswick on May 29 as part of volunteers week before moving on to meet campaigners from the group Speak Out.
However following an operation on her teeth last week she was unable to make it. Ann was planning on listening to Speak Out's campaign to improve toilet facilities for severely disabled people within the borough.
A spokesman for the Brentford & Isleworth Labour MP said: "Ann was very disappointed to have had to cancel her engagements on Friday due to illness and she gave her apologies in advance accordingly.
"It's extremely rare for Ann to be off work due to illness, as she usually works from dusk till dawn in Brentford, Isleworth and Westminster, but these things do tend to sometimes happen to everyone."