Charlotte and Maggie are among the favourites for the name of the Prime Minister’s new daughter.
Allegra - the name of his former aide who resigned over the Christmas party scandal - has also been listed as a 50-1 outsider.
Mr Johnson and his wife Carrie announced the birth of their daughter on Thursday morning and bookmakers immediately made Charlotte, the name of his late mother, the 3-1 favourite with Maggie at 7-2.
Other potential names include Elizabeth at 12-1, Theresa at 33-1 and Borissa at 100-1.
Mr and Mrs Johnson announced the birth of a “healthy baby girl” at a London hospital and the Prime Minister was understood to be present throughout the birth.
A spokeswoman for the couple said: “Both mother and daughter are doing very well. The couple would like to thank the brilliant NHS maternity team for all their care and support.”
The couple announced they were expecting their second child together.
At the same time, the 33-year-old environmental campaigner spoke of having a miscarriage earlier in the year.
Already the couple raise their son Wilfred and have introduced him to his new baby sister.
Charlotte Johnson Wahl died “suddenly and peacefully” at St Mary’s Hospital in Paddington at the age of 79 in September, according to a death notice in The Times.
Mr Johnson once described his mother as the “supreme authority” in the family and credited her with instilling in him the equal value of every human life.
