Miranda Hart calls off Call the Midwife return

Chummy, pictured with husband Peter (Ben Caplan), was expected to return this Christmas

Miranda Hart will not be returning to her role as "Chummy" in BBC One's Call the Midwife, as was reported in April.

The comedian and actress said it was "with a heavy heart" that she had to call off her comeback to the series.

"Having shared Chummy's return to CTM, I've not been able to birth (pun) the schedule to make it work," she tweeted.

It had been hoped that Camilla "Chummy" Noakes would return for the 2016 Christmas special and the sixth series, expected to air in 2017.

Hart, who left the show during its fourth series due to work commitments, said she was "truly sad not to be playing Chummy this year".

Dame Harriet Walter will join the cast for the show's sixth series

But she said fans were "in for a treat" with the addition of Dame Harriet Walter as a cast member, "and more besides".

Hart's character was last seen moving to a mother and baby unit.

Based on the memoirs of the late Jennifer Worth, Call the Midwife tells of midwives working in east London in the 1950s and '60s.

Hart received a Bafta nomination in 2012 for her work in the series, which also stars Jenny Agutter, Helen George and Judy Parfitt.

Dame Harriet, 65, is set to play a new character, Sister Ursula, when the show returns next year.