The former Peep Show star underwent major heart surgery two years ago, and said on Wednesday that Strictly “and its demanding schedule” had begun to take their toll on his recovery.
He said: “I’m extremely sorry to announce that I’m withdrawing from Strictly Come Dancing due to ill health.
“Two years ago I had open heart surgery and although I believed I was fit enough to take on Strictly and its demanding schedule, it became clear that I had bitten off more than I could chew for this stage in my recovery.”
Robert continued: “I had begun to feel symptoms that led me to seek an urgent consultation with my heart specialist, and it was her view that it would be better for the sake of my health to step back from the show.
“I’m proud of the three dances that Dianne Buswell and I managed to perform and I deeply regret having to let her down like this.
“I couldn’t have wished for a more talented partner or more patient teacher, and it’s a measure of Dianne’s professionalism and kindness that I was able to get as far as I did.”
“I’ve been especially touched by the support from fellow heart patients,” Robert added. I think perhaps I was too eager to impress them.
“They will know that recovery doesn’t always go in a straight line, and I hope they’re not too disappointed that I ran into the limits of my resilience sooner than I’d hoped.”
The comedy actor’s professional partner Dianne Buswell said of the news: “As a massive fan of Robert’s I was delighted to find out he was joining the Strictly family. On top of this, to find out he was my partner was the icing on the cake.
“We made a great team, worked hard and had a good laugh along the wa. I am so proud of the three amazing dances we produced. I know Robert had a lot more to give to the competition, but his health of course comes first and I wish him a speedy recovery.
“I feel lucky to have danced with him and to call him a friend.”
Robert’s exit leaves 12 couples still in the competition, following the departures of soap stars Nina Wadia and Katie McGlynn earlier in the series.
Strictly continues on Saturday night at 7pm on BBC One.